Varia

1a On stems and leaves => 3

1b On flowers => 2

2a Flowers ± swollen globularly, unopened. Inner organs soon destroyed and replaced by spore balls consisting of a yellowish-brown powdery dust. Arenaria pungens; Minuartia hybrida: Thecaphora saponariae s.l.

2b Flowers outwardly not conspicuously changed; anthers shortened and swollen; later on filled with a dusty violet spore powder. M. recurva: Microbotryum violaceum

3a Malformations caused by fungi fruiting at surface => 5

3b Malformations caused by animals => 4

4a Leaves on slightly stunted shoots more densely arranged, the leaf blades a little deflected over their tip, curved upwards at margin. Honckenia peploides: Myzus certus

4b Shoot axis stunted, bent at infestation site. Leaves more clustered, leaf blades distorted. Honckenia peploides: Philaenus spumarius

5a Leaves or stem with rotund- oblong-oval, yellowish brown pads, occasionally slightly bent, protruding on underside, soon bearing a brown sorus at surface. Arenaria montana, retusa, serpyllifolia, tenuifolia; Minuartia hybrida, laricifolia, verna: Puccinia arenariae

5b Systemic diseased shoots growing rigidly erect; leaves reduced, slightly thickened and ± bent, spoon-like. On leaf underside and stem grey down of conidiophores develop. Honckenia peploides: Peronospora honckenyae

5c Bushy accumulation on twisted and thickened stems; capsules inflated. M. viscosa: Inducer unknown

1a On parts above ground => 2

1b Roots with nodular swellings. M. annua: Meloidogyne hapla

2a Inducer living inside galls => 4

2b Inducer living and/or fruiting on gall surface => 3

3a Young leaves of disfigured shoot tip curled. M. annua, perennis: Aulacorthum solani

3b Orange-yellow, soon dusty, spindle-shaped, ± distorted bulges of various length on underside of main venation, on petioles as well as occasionally on young stem parts. Patches developing on leaf blades are small, rotund and not swollen. M. perennis: Melampsora populnea

4a Stem or leaves with localised, well defined galls => 6

4b Malformations usually extending over several organs => 5

5a Large parts, sometimes the entire plants, including primordia of flowering parts, with vitreous, pearl-like, compound small warts; these often join into crusts or ridges and variously disfigure the severely stunted plants during their development. M. perennis: Synchytrium mercurialis

5b On M. annua. Young plants severely stunted. Internodes spongy, swollen, pale green. Leaves distorted, with ± swollen stalks and veins. Ditylenchus dipsaci

6a Rotund, one-chambered swellings on stems, leaf- or inflorescence axial parts. Containing a single curved larva. M. annua. Kalcapion semivittatum

6b Slender, narrow and compact, about 5–30 mm long, soon browned upwards roll of leaf margin. M. perennis: Thrips fulvipes

1a Galls on parts above ground => 2

1b Side roots often with many nodular to spindle-shaped swellings, which bear some lateral roots. Meloidogyne hapla

2a On flowers or inflorescences => 5

2b On vegetative organs => 3

3a Large parts of plant disfigured => 4

3b Leaf blade, especially in venation, with rotund to ± acuminated, oval, often conspicuous yellow to yellow-brown swellings, occurring especially on underside, which are marbled, sieve-like. Occasionally on stems. Puccinia recondita

4a Growth stunted, leaves rolled downwards, curled. Also on disfigured, ± etiolated flowers. Dictyla echii

4b Basal stem parts variously swollen, spongy ± pale green. Ditylenchus dipsaci

5a Inflorescence clustered, ball-like. Brachycaudus helichrysi

5b lowers greened, densely white pubescent, clustered, ball-like. Aceria eutricha

1a On above-ground parts => 2

1b Nodular swellings on roots. Lilium spp.: Meloidogyne hapla

1c Conspicuous galls on subterranean buds. Lilium spp.: Rhodococcus fascians

2a On severely etiolated flower buds which are occasionally galled => 3

2b Pale, sometimes brownish margined, occasionally inconspicuously swollen spots on leaves and stems, occupied by hardly protruding cups, up to 1 cm long. L. bulbiferum, canadense, candidum, carniolocum, martagon: Uromyces aecidiiformis

2c Underside of the leaves with a whitish fungal down consisting of vertical conidiophores that apically are dichotomously branching several times, each branch ending in an elliptic conidium. L. candidum: Peronospora lilii

3a Malformations lacking additional pubescence => 4

3b The ± disfigured flower buds or also the slightly spreading perianth leaves are covered with long white hairs. Containing many pale yellow larvae. L. martagon: Contarinia martagonis

4a Malformations caused by larvae with inconspicuous head => 5

4b Malformations caused by larvae with distinct head. Flower buds usually not opening, partially swollen, ± crippled, sometimes bent on one side, containing several yellowish-white, elongate oval larvae, which feed on variously disfigured stamens and ovaries or mine into the perianth leaves or also extend into the flower peduncles. L. martagon, rarely candidum: Liriomyza urophorina

5a The compact, mostly stunted buds contain several yellowish, jumping larvae. L. martagon: Contarinia lilii

5b lower buds severely stunted and etiolated. Larvae red. L. candidum: Contarinia liliacea

1a On above-ground parts => 2

1b Roots with many nodular or elongated spindle-shaped swellings, about 0.5–5 mm long and 3–5 mm broad, ± obliquely bent, crooked; containing eelworms inside the ± spongy tissue. Subanguina radicicola

2a On vegetative parts => 3

2b Inflorescence variously disfigured and bleached. Aceria tenuis

3a Malformation with black fungus sori => 5

3b Galls in culm, caused by animals => 4

4a Culm locally weakly swollen; containing a single larva. Tetramesa brischkei

4b Culm stunted in development. Upper internode sometimes appearing thickened. Inflorescence aborted, stuck in the sheaths, disfigured and ± dishevelled. Containing a yellowish-white, up to 4 mm long larva. Oscinella pusilla

5a Diseased shoots at first showing enhanced development; number of internodes and leaves increased. Organs weaker and usually paler than healthy ones. Leaves rigid, erect; plant looking weak; exceptionally with primordia of usually crippled and curved inflorescences. Internodes below the leaf sheaths, rarely also the sheaths, with expanded smut sori developing, on their surface. Tranzscheliella hypodytes

5b Smut patches on the leaves or sheaths. Ustilago striiformis

1a On above-ground parts => 2

1b Roots with several small, spindle- to nodule-shaped swellings, bearing lateral roots. Meloidogyne hapla

2a On vegetative parts => 3

2b Florets ± stunted and greened. Unidentified gall mite

3a On leaves => 4

3b Irregular swelling in stem, up to 6 cm long by 10 mm wide; containing several chambers each with a white larva or pupa. Timaspis lampsanae

4a Galls mainly in leaf blade => 5

4b Petiole, mid- and main veins or also the leaf blades of the rosette leaves already in early spring with conspicuous, usually reddish margined or overflowed, yellowish, aecia bearing bulges. Puccinia lapsanae

5a Expanded malformations of leaves => 6

5b Leaf blades with rotund wide pads, up to 5 (7) mm, usually protruding on the underside and concave on the upper side, bearing ± deep yellow aecia. Exceptionally also spindle-shaped galls on bent leaf ridges and petioles. Puccinia opizii

6a Curvings and curlings of the leaf blade caused by aphids => 7

6b Leaf blade more or less deflected, ± bulge-like curled, dark green coloured, close to the froth-covered nymph occasionally a clustering of disfigured leaves on often one-sided stunted, bent shoots. Philaenus spumarius

7a Distinct malformations of the leaf, associated with deflected curving of the margin and curling of the leaf blade. Aphid 1.8–3 mm long, straw yellow, green or reddish; wingless adults on the dorsal side with a pattern of dark spots. Siphunculi slender, cylindrical. Nasonovia ribisnigri

7b Similar malformations. Aphid 2.5–3.5 mm long, body white. Siphunculi notably swollen, widest in the middle. Hyperomyzus lampsanae

1a On parts above ground => 2

1b Oval to cylindrical, also hand-shaped to coralloid branched nodules, laterally attached to the roots; occasionally coalesced into larger clusters. Laburnum spp.: Rhizobium leguminosarum

2a On inflorescences or pods => 5

2b On vegetative organs => 3

3a On axial parts => 4

3b Buds swollen, walls of cavity inside lined with black mycelium. L. anagyroides: Asphondylia sp.

3c Leaves stunted, sometimes deflected over their top, margin ± curved downwards, leaf blade folded or curled. Laburnum alpinum, anagyroides, watereri; Lembotropis nigricans: Aphis cytisorum

4a Thicker branches with spindle- to club-shaped swellings bearing mistletoe. Laburnum spp.: Viscum album

4b Bark of young shoots with rimmed depressions, each containing a flat froth-covered nymph. Laburnum spp.: Chionaspis salicis

5a nflorescence variously disfigured. Laburnum anagyroides; Lembotropis nigricans: Aculops cytisicolus

5b Fruit with conspicuous swelling. Laburnum spp.: Inducer unknown

1a On parts above ground => 2

1b Roots with nodular, compact swellings. F. x intermedia: Meloidogyne hapla

2a Galls on twigs => 3

2b Leaves on shoot tips ± disfigured, caused by aphids. F. suspense: Unidentified aphid

3a Rotund galls, usually situated on nodes, developing into strongly fissured woody proliferations, up to several cm large. F. suspense: Agrobacterium tumefaciens

3b Conspicuous, ± wart-like, at first succulent, later on tough galls of variable size, which develop on young shoots instead of lateral buds. Rhodococcus fascians

1a On parts above ground => 2

1b Roots with ± spindle-shaped, fleshy swellings, containing masses of minute spores. Plasmodiophora brassicae

2a Malformations at surface with sori of fungus => 5

2b Malformations caused by animals => 3

3a On stems, leaves or flowers => 4

3b Fruit slightly swollen, often oblique. Containing a single larva. Unidentified beetle

4a Complete plant ± disfigured, leaves usually shorter and broader, ± arched. Inflorescence stalk stunted. Flowers stunted tuft-like, ± greened or leafy, sometimes abnormally pubescent. Cecidophyes borealis

4b Similar malformations. Aceria drabae

4c Stem at base with swelling up to 4–7 mm long and 2–4 mm thick. Containing a single white larva. Ceutorhynchus hirtulus

5a Sori expanded, consisting of branched conidiophores. Plant completely or largely stunted, sometimes excessively leafy. Leaves etiolated, pale, slightly thickened, sometimes arched spoon-like. Infected stem parts shortened, thickened, ± bent. Inflorescences and buds stunted. Hyaloperonospora erophilae

5b At the tip of the older leaves of the rosette a faint fungal down, consisting of erect, distally strongly branched conidiophores. The plant is not disfigured, and the leaves are not bleached or galled. Hyaloperonospora praecox

5c Sori compact, at first closed, glossy, porcelain-like, with mealy dusting after rupturing; short bulge-like to long expanded. On all green parts. Infected stems often distorted; inflorescences ± disfigured. Diseased flowers with conspicuously enlarged calyx and ovaries. Albugo candida

1a On the leaflet leaf blades => 2

1b Tip of frond shortened, spirally rolled upward, including the crowded, only slightly changed side leaflets making a conspicuous nest with a white larva on the ± thickened midrib. D. carthusiana, cristata, dilatata, filix-mas: Chirosia betuleti

2a Leaf blade on underside sometimes ± fleshy because of enlarging of mesophyll- or epidermis cells; occasionally swollen, almost blister-like yellowish-brownish discoloured; fungus galls => 4

2b Malformations caused by animal parasites => 3

3a Leaflets with small pustules which contain eggs, mainly situated at margin, rapidly becoming necrotic after larval emergence. “Procecidia”, oviposition scars, not true galls. D. filix-mas: Aneugmenus coronatus

3b Margin of leaflets folded, discoloured, slightly thickened. Thelypteris palustris: Undescribed gall midge

3c Rounded swelling on rachis, about 2 mm long; containing a pale green caterpillar which bites a hole and ejects froth that covers the gall. Dryopteris spp.: Blasticotoma filiceti

4a On D. campyloptera and relatives

I Mycelium intercellular. Causes ± fleshy localised swellings in tissues of thickened leaflets. D. carthusiana, dilatata: Taphrina filicina

II Mycelium only below cuticule

a Often distinctly protruding galls on leaflets, up to 5 mm broad, ± fleshy. D. carthusiana, dilatata, “rigida var. australis”, villarii: Taphrina fusca

b Up to 5 mm long galls on leaf blade. D. carthusiana, dilatata, filix-mas: Taphrina athyrii

4b On D. affinis, borreri, carthusiana, filix-mas. Small, up to 5 mm long, often many per leaf blade, ± fleshy swollen, yellow-greenish to brownish galls: Taphrina vestergrenii

1a On parts above ground => 2

1b Roots usually with laterally inserted oblong-oval or cylindrical swellings, apically often forked or branched, almost coralloid, sometimes clustered. Dorycnium spp.: Rhizobium leguminosarum

2a On flowers or fruits => 5

2b On vegetative parts => 3

3a On shoot tips or leaves => 4

3b Shoot axis with oblong, reddened swelling. D. pentaphyllum subsp. Germanicum: cf. Melanagromyza cunctans

3c Conspicuous spindle-shaped swelling, bright red coloured, flattened on one side, with rimmed depressions containing the causer. D. pentaphyllum: Planchonia arabidis

4a Leaflets folded. D. pentaphyllum subsp. germanicum + herbaceum: Unidentified gall mite

4b Terminal leaflets of leaf folded, pod-like, reddish discoloured. Containing several at first yellowish-white later orange larvae. D. hirsutum: Dasineura sp.

4c Tip of side shoot with greenish, closed, strongly white pubescent gall, up to 7 mm long and 3 mm thick. D. hirsutum, pentaphyllum: Asphondylia dorycnii

5a Galls on pods => 6

5b lowers disfigured and ± greened, as well as other organs present on shoot tip variously disfigured organs abnormally pubescent. Dorycnium spp.: Aceria euaspis

6a Pod swollen. Inner wall covered with fungus. D. hirsutum, pentaphyllum: Asphondylia dorycnii

6b Pods swollen; mycelium absent. Containing a curved larva with head capsule. D. pentaphyllum & subsp. germanicum + herbaceum: Ischnopterapion aeneomicans

1a On above-ground parts => 2

1b Side roots with nodular swellings. D. sativus: Meloidogyne hapla

2a On vegetative parts => 4

2b On capitula => 3

3a Infected capitula often strange-looking. Several petals enlarged, ± disfigured, discoloured. Anthers and ovaries largely aborted. Loose down of branched conidiophores on petals of usually completely diseased capitula. D. fullonum, laciniatus, pilosus: Peronospora violacea

3b Many parts of capitula disfigured; diseased tissue hypertrophied, soon browning and dying. Infected fruits reduced, twice as thick as normal ones; pappus sessile, swollen. Seed coat thickened, rounded. D. fullonum, sativus: Ditylenchus dipsaci

4a Malformations on rosette leaves => 6

4b Malformations of higher situated parts => 5

5a Leaf blades of larger stem leaves, including tip, mainly deflected on one side; strongly curled and deep green close to the froth-covered nymph. Dipsacus spp.: Philaenus spumarius

5b Undescribed gall-like malformations caused by aphids. D. sativus: cf. Aulacorthum solani

= On D. laciniatus and D. fullonum the gall mite Leipothrix dipsacivagus has been described causing rusting and wrinkles on the longitudinal folds of leaves

6a Usually several inner leaves of spring rosettes infected, more erect; leaf blades narrowed, slightly thickened and ± brittle; usually to a large extent the infected parts alongside the midrib are pale green, bulging upwards over the normally coloured marginal areas, covered on underside by a dirty pale grey down of branched conidiophores. D. fullonum, laciniatus, pilosus: Peronospora dipsaci

6b Rosette leaves in spring stunted, shortened, spongy and swollen, especially at base, pale, sometimes clustered, cabbage-like. D. sativus: Ditylenchus dipsaci

6b Leaves with small gregarious pustules, less than 0.5 mm across. D. fullonum: Synchytrium succisae

1a On leaves and stems => 3

1b On roots or on root collar => 2

2a Roots with conspicuous spindle-shaped or acuminated, cylindrical succulent, compact swellings. C. abyssinica, maritima, tataria: Plasmodiophora brassicae

2b Rotund, about pea-size, one-chambered galls on root collar. Containing a single larva. C. maritima: Ceutorhynchus assimilis

3a Expanded malformations caused by aphids => 5

3b Galls of lesser expansion, ± pad- or bulge-shaped => 4

4a Galls spindle-shaped, 15‒20 mm long, also green inside, on petioles, leaf veins or thinner stems. Containing a single larva. C. abyssinica, maritima, tatarica: Ceutorhynchus chalybaeus

4b At first closed glossy, porcelain-like, later on rupturing and with mealy dusting, rotund to oblong-oval pads or bulges on leaves, stems and stalks of inflorescences. C. maritima, tatarica: Albugo candida

4c Stem and also axis of inflorescence usually with expanded, conspicuous, often distorted swellings, soon covered with a down of branched conidiophores. Flowers of diseased inflorescences severely stunted. Leaves of axillary shoots if infected early, ± spoon-like arched, thickened, brittle, pale green; with a dense down of conidiophores on underside. C. maritima, tatarica: Hyaloperonospora parasitica

5a Complete plant disfigured, leaves rolled, flowers greened. C. maritima: Lipaphis hedickei

5b Leaf blades of basal leaves with irregular paler green, sometimes ± red-violet marbled archings. C. abyssinica, maritima: Brevicoryne brassicae

1a On inflorescences or fruits => 5

1b On vegetative parts => 2

2a Malformations caused by animal parasites => 3

2b Bulge-shaped, sometimes distorted, about 10 mm long swellings on leaf veins, -midrib and -stalk, bearing cinnamon-brown uredinia, occasionally also on younger stem parts and even in inflorescence. Puccinia conii

3a Malformations caused by aphids => 4

3b Leaf blade over large parts nest-like downwards deflected; leaf tips slightly curled and deep-green. Philaenus spumarius

4a Axis of leaf tip conspicuously distorted and twisted; leaf blades folded and curled. Aphid about 2 mm long; pale green, with pale siphunculi, these much longer than cauda, which bears an appendage. Antennae shorter than half the body length. Cavariella pastinacae

4b Malformations similar. Aphid 1.5–2.4 mm, grey-green, often blackish-brown. Siphunculi very dark, about as long as cauda. Antennae ⅓–½ body length. Hyadaphis foeniculi

5a Stalk at centre of (partial) umbel ± globular to club-shaped swollen. Inner wall covered with mycelium. Containing a red larva. Lasioptera carophila

5b Fruit strongly swollen, globular to rotund-oval; galls protruding above the umbel; glabrous, ± reddened. Containing an orange-red larva. Kiefferia pericarpiicola

5c Inside disfigured fruits of C. maculatum develop uredinia of Puccinia conii

1a On leaves and shoot => 2

1b Lateral roots with 2–4 mm long, ± spindle-shaped swellings, with some partially adventitious roots. Meloidogyne hapla

2a Malformations by aphids and spittlebugs => 3

2b Stems of young plants very much shortened, spongy, swollen, bushy clustered; petioles of basal- or stem leaves, sometimes including the under leaf blade areas galled in a similar way. Ditylenchus dipsaci

3a Malformations by aphids => 4

3b Leaves on the stunted and ± bent stem nest-like converging; curled and dark green close to the froth-covered nymph. Philaenus spumarius

4a Malformation, curling and curving of apical young leaves, caused by yellowish or greenish aphids => 5

4b Similar malformations caused by black aphids. Aphis fabae

5a Malformations by yellowish to bright green aphids lacking segmentally arranged brown dots on the dorsal surface. Brachycaudus helichrysi

5b Adult apterous aphids yellowish, possessing segmentally arranged brown dots on the dorsal surface. Myzus ornatus

1a On stems or leaves => 2

1b Centre of umbel- or partial umbel stalk swollen ± club-shaped or globular; sometimes ± spindle-shaped galls on stalks close to branching points. Containing a single orange-yellow to red larva. Lasioptera carophila

2a Malformations mainly on leaves => 3

2b Stem of young plants below the attachment of petiole swollen, barrel-shaped, also partially distorted. Complete plant stunted. Leaves ± curled and rolled. Containing a white larva. Unidentified gall midge

3a Leaves distorted or rolled inwards, ± curled => 4

3b Leaf rachis and -stalk, also stem, with, ± distinctly swollen, oblong-oval, yellowish bulges, up to about 4 mm long bearing spermogonia and brown sori of 1-celled uredinia. Puccinia nitida

4a Malformations caused by aphids => 5

4b Stem of developing plants locally stunted, sometimes distorted; leaves clustered, their tips ± nest-like converging downwards, partially curved. Infected umbels variously stunted and distorted; flowers ± disfigured. Containing a froth-covered nymph. Philaenus spumarius

4c Leaves on the underside with a white fungal down of erect conidiophores that apically bear a few short branches, each one ending in a conidium. Plasmopara anethi

5a Younger leaves variously distorted. Tips curled. Aphid black. Aphis fabae

5b Similar galls caused by green aphids with “double” cauda.
Cavariella aegopodii and/or C. pastinacae

1a On inflorescences, florets or fruits => 6

1b On leaves, stems or stalks of ± undeveloped panicles => 2

2a Several internodes of the initially elongate culm occupied by extensive patches of smut. Also on possible primordia of panicles; sometimes on leaves => 5

2b Malformations caused by animal parasites => 3

3a Culm with elongate spindle-shaped swellings => 4

3b Inner side of leaf sheaths covering parts of culm, or undeveloped stalks of panicles and occasionally even the glumes, often with long expanded rows or crusts of blister-like, at first white, then dark brown tuberculi. S. capillata: Steneotarsonemus graminis

3c In similar galls on S. capillata, pennata: Steneotarsonemus canestrinii

4a Culm above the 3th or 4th node with oblong, weak swelling. Pith containing a single larva. S. capillata: Tetramesa aciculata

4b Elongate spindle-shaped, weak swelling on culm of S. pennata. Containing a single larva. Tetramesa sp.

4c On S. capensis: Tetramesa stipae

5a Culms and possibly stalks of inflorescences with expanded blackish patches of smut on all sides. S. capillata, pennata: Sphacelotheca valesiaca

5b Similar infestation. Spores smaller, 4–6 x 3–5µ, reddish-brown, glabrous. S. capillata, dasyphylla, eriocaulis, pennata, pulcherrima: Tranzscheliella minima

6a Midrib of spikelets abnormally elongated, with swellings up to about 10 mm long, spindle-shaped, occasionally 2- or 3-winged, grain-like, sometimes ± curved. Containing a single larva. S. borysthenica, eriocaulis subsp. austriaca, pennata: Tetramesa scheppigi

6b Glumes and flower parts coalesced, transformed into a 7–10 mm long, elongate spindle-shaped, fruit-like gall. Containing a single larva. S. capillata, parviflora: Tetramesa cylindrica

6c Spikelet swollen, with lateral exit hole. S. capillata, parviflora: Tetramesa cylindrica

1a On parts above ground => 2

1b Roots with nodular to slender spindle-shaped swellings, bearing some side roots. S. arvensis: Meloidogyne hapla

1c Roots inside with giant cells, outwardly hardly changed or with excessive development of side roots above the infestation site. S. arvensis: Heterodera schachtii

2a Malformations of expanded parts of plant => 3

2b Local, rotund- to oblong-oval pads, sometimes resulting in distortions, up to about 5 mm long, occasionally slightly thickened, often yellow-margined, soon covered with 2-celled brown telia.  S. arvensis, morisonii, pentandra: Puccinia arenariae

3a Malformations caused by fungi which fruit at surface => 6

3b Malformations caused by animals => 4

4a Parasites live at surface of malformations => 5

4b Young plants completely stunted. Stem severely stunted, especially spongy, swollen at base. Basal- and gall-bearing leaves similarly disfigured. Containing many eelworms. S. arvensis, pentandra, morisonii: Ditylenchus dipsaci

5a Stem terminally stunted; organs clustered, with reduced and bent leaves and partially also with stunted, disfigured flower buds; flowers a little opened, ± greened and leafy. S. arvensis, pentandra: Inducer unknown – ? gall mite

5b Gall-like twisting, bending or S-shaped or right-angled distortion of ± discoloured leaves. S. arvensis: Taeniothrips atratus

6a Internodes of strongly infected young plants shortened, slightly thickened, sometimes curved. Leaf whorls accumulated; leaves stunted, pale green, slightly swollen as result of defective differentiation of tissue. The usually many diseased flower buds ± bloated, globular. All diseased parts soon covered with a loose down of branched conidiophores, partially containing oospores. S. arvensis: Peronospora obovata

6b Similar malformations on S. morisonii, pentandra: Peronospora vernalis

1a On stalks of umbels, flowers or fruits => 6

1b On leaves => 2

2a Localised or extensive malformations caused by animal parasites => 5

2b Small wart-shaped or larger spindle-shaped galls caused by fungi => 3

3a Galls mainly wart-shaped; spores inside host tissue => 4

3b Leaf veins, -midrib or -stalk spindle-shaped, swollen, galls usually conspicuous, sometimes ± curved, often with yellowish margins; bearing dark brown spores. Puccinia angelicae

4a Galls less than 1 mm across, multi-cellular, wart-shaped, ± golden-yellow; usually many on basal leaves, on stalks, midrib as well as on stems; sometimes coalescing into crusts or ridges. In central nutritive cell an up to 180 µm large perennial (“dauer”) sporangium. Synchytrium aureum

4b Galls similar, usually larger, ± black-brown; often clustered into densely situated groups on ± curved leaf veins, -axis or -stalk. Nutritive cells with several, ± rotund, 20–35 x 15–30 µm large perennial (“dauer”) spores. Physoderma vagans

5a Leaf blades and tips of leaflets on the often stunted midrib folded over the midrib or otherwise distorted; ± discoloured and thickened. Containing several yellowish, terminally ± reddened larvae. Jaapiella dittrichi

5b Leaf blade curved; often with curled side leaflets ± clustered, nest-like. Philaenus spumarius

6a On flowers or fruits => 7

6b Centre of (partial) umbel or stalk of umbel ± swollen, club-shaped. Inner wall covered with mycelium. Containing a red larva. Lasioptera carophila

7a Flower bud unopened, swollen to a globular or obovate gall. Unidentified gall midge

7b Fruit disfigured into a bladder-like swollen, often reddened, thin-walled gall, protruding above the partial umbel. Containing 1 (–3) orange-red larvae. Kiefferia pericarpiicola

1a On parts above ground => 2

1b Roots with nodular swellings. R. minor, serotinus: Meloidogyne hapla

2a On shoot tips, stems or leaves => 4

2b On flowers => 3

3a Flowers transformed into white-woolly, felt-like, succulent masses. Containing many larvae. R. alectorolophus, angustifolius, crista-galli, minor: Rhopalomyia cristaegalli

3b Flowers unopened or half opened. Calyx normal. Corolla poorly developed, reduced, greenish. Stamens and ovaries ± reduced. R. angustifolius: Taeniothrips atratus

4a On stems and leaves => 5

4b Side shoots terminally stunted. Younger leaves clustered, stunted, folded upwards, sometimes ± distorted, transformed into a bud-like to loose tuft-like gall, about 5–8 mm long. Between the mainly basally thickened leaf blades live yellowish-white larvae. R. angustifolius, serotinus: Macrolabis sp.

5a Malformations with erinea, consisting of hairs or conidiophores, on underside of leaves and occasionally also on stems => 8

5b Curling of leaf or swelling of stem => 6

6a Curling of several, usually terminal leaves => 7

6b Shoot axis sponge-like thickened to varied extent, ± curved. More strongly infected plants conspicuously stunted. R. angustifolius: Ditylenchus dipsaci

7a Shoot tip stunted, sometimes curved to one side. Leaves shortened, deflected, locally strongly curled and deep green. R. alectorophus, angustifolius, minor: Philaenus spumarius

7b Tips of vegetative shoots ± stunted. Leaves clustered, slightly curled and deflected. Infected inflorescences with slightly disfigured bracts and ± lacerate flowers. R. alectorolophus, angustifolius: Brachycaudus helichrysi

8a Completely diseased shoots develop faster than healthy ones, internodes thinner and longer, leaves paler, narrowed, appearing arched by deflection of margins. On the leaf underside, usually of the complete leaf blade, a very dense layer of branched conidiophores develops; usually absent from stem parts. R. alectorolophus, alpinus, angustifolius, glacialis, minor, serotinus: Plasmopara densa

8b Underside of the leaves with a greyish purple fungal down, consisting of erect, distally repeatedly dichotomously branched conidiophores. The conidia are elliptic. The host plant does not become disfigured. R. alectorolophus, angustifolius, serotinus: Peronospora pocutica

8c Leaf underside completely or partially with white floccose pubescent pads. Hairs branched or ± club-shaped. Erinea also occurring on stems. R. angustifolius: Unidentified gall mite

1a On parts above ground => 2

1b Roots with nodular swellings. P. tuberosa: Meloidogyne hapla

2a Leaf blades, stalks or stems with fruiting bodies of rust fungi or leaf blades with erinea => 9

2b Galls caused by insect larvae => 3

3a Galls on vegetative parts => 4

3b Galls caused on inflorescences and flowers. Flower heads contain gall wasp larvae. P. tuberosa: Aulacidea dyakonchukae

= As causer of flower galls, one more gall wasp has been described for P. tuberosa, namely Vetustia investigata

= The gall wasp Panteliella bicolor causes on P. tuberosa outwardly inconspicuously disfigured stems

4a Leaf galls => 6

4b Stem galls caused by cynipid larvae => 5

5a The empty inside of the stem is filled up with monolocular, thin-walled, white, rounded galls, up to 2 mm in diameter. P. tuberosa: Aulacidea phlomica

5b Similar stem gall without externally visible malformation. P. tuberosa: Phanacis phlomidis

6a Leaf galls contain gall midge larvae lacking conspicuous mouth parts => 8

6b Leaf galls contain gall wasp larvae with conspicuous mandibles => 7

7a Leaf blade on upper side with globular, 2–3.5 mm long galls; covered with long, white hairs; on underside conspicuous as small tuft. Containing a single larva. P. tuberosa: Panteliella fedtschenkoi

7b Veins with yellow to brown, spindle-shaped, 1–3 mm long swellings; two larval chambers per gall each containing a single larva. P. tuberosa: Panteliella sp.

8a Subglobular gall, 3–5 mm across, protruding equally on both sides of leaf blade, often close to margin, which is incised; sometimes on petiole, rarely on stem. One-chambered, thin walled. P. cretica, fruticosa, tuberosa: Asphondylia phlomidis

8b Flat irregular pustules on leaves, 3-4 mm in diameter, on the upperside slightly greener than the remaining part of the leaf, on the lower side of the leaf with a slightly hypertrophied epidermis and a partly swollen vein; inside each gall is a chamber where two to four larvae develop together. Usually four to six galls develop on one leaf but up to sixty galls were found on one leaf. In such cases the galls are joined, forming a large irregular pustule with several separated chambers. Larvae pupate in galls, each larva in a white cocoon. P. fruticosa: Phlomidiomyia pustularis

9a Galls with fruiting bodies of fungi on surface => 10

9b Leaf underside with erinea, infestations ± arched. P. tuberosa: Unidentified gall mite

= Similar galls, caused by unidentified gall mites, have been described for P. samia and P. herba-venti subsp. pungens

= The gall mite Aceria onychia causes abnormally hairy disfigured parts on Phlomis fruticosa, tuberosa

10a Up to 10 mm broad, yellow, rotund sori, protruding on underside bearing aecia, on upperside ± depressed pads with spermogonia or ± elongated bulges on main venation, on petioles and young stems. P. tuberosa: Puccinia stipina

10b Aecia on underside, especially on expanded parts or on complete leaf blade; sori occasionally also on petioles and stems, weakly disfiguring the infected organs. Phlomis spp.: Puccinia phlomidis

1a On parts of flowering- or fruiting inflorescences => 6

1b On stems and leaves => 2

2a Expanded malformations of variable shape => 4

2b Oval or spindle-shaped galls on stems, petioles or leaf veins => 3

3a Small galls on root collar or stem base or leaves of young plants, basally distinctly broadened and swollen. Containing a single larva. Calosirus terminatus

3b Spindle-shaped, sometimes coalescing, usually only weak and slightly expanded bulges on petioles, midrib, main veins and young stems. Puccinia nitida

4a Malformations mainly of leaf blades => 5

4b Petioles, midrib, sometimes also the basal parts of leaflets of severely stunted young plants are variously disfigured, swollen and spongy. Ditylenchus dipsaci

5a Leaf midrib ± shortened and curved, with clustered, curled, deflected leaflets. Philaenus spumarius

5b The tips of leaflets, usually of many severely stunted and disfigured leaves, are deflected and sometimes swollen and tuberculate. Trioza apicalis

5c Malformation caused by aphid. Upper leaves curled, lower leaves atrophied; leaf blade sometimes arched downwards and curled on upperside. Hyadaphis foeniculi

6a Centre of umbel or stalk of umbel ± swollen, club-shaped. Inner wall covered with mycelium. Containing a red larva. Lasioptera carophila

6b Fruit strongly inflated, bladder-like; galls ± reddened, protruding above the umbel; containing a single orange-red larva. Kiefferia pericarpiicola

1a On parts above ground => 2

1b Roots with nodular swellings. O. stricta: Meloidogyne hapla

2a On vegetative organs => 4

2b On flowers and fruits => 3

3a Flowers greened, ovaries elongated. O. acetosella, articulata, corniculata, stricta: Aceria oxalidis

3b Anthers and ovaries slightly swollen, later on containing reddish-brown spores. Diseased capsules sterile. Infestation not distinct before dusting of spores. O. fontana, stricta; not on O. corniculata: Thecaphora oxalidis

4a Malformations extended over several organs => 6

4b Galls localised => 5

5a Less than 1 mm long, sometimes joined, yellow many-celled warts on basal leaf- and stem parts. O. stricta: Synchytrium aureum

5b Slightly thickened cushions on leaves and petioles, with distinctly arched, cup-shaped aecia. ~, in NW-Eu on O. corniculata, fontana, stricta: Puccinia sorghi

6a Leaflets stunted, shorter stalked. Leaf blade rolled inwards, ± folded and twisted, finely wrinkled. O. acetosella, articulata, corniculata, stricta: Aceria oxalidis

6b Plant stunted, variously disfigured. Oxalis spp.: Aphis fabae

1a On parts above ground => 2

1b Roots with small, nodular or spindle-shaped swellings. O. verna: Meloidogyne hapla

= Cysts of a Heterodera species may occur on this host

2a On vegetative parts => 3

2b Ovaries irregularly swollen, containing a yellow larva. O. verna: Unidentified gall midge

3a Single galls wart-shaped, caused by fungi fruiting inside the host cells => 6

3b Malformations more expanded => 4

4a Malformations caused by fungi, fruiting at surface or sporulating after rupturing of bulges => 5

4b Spindle-shaped or irregularly expanded, spongy, pale-green swellings on stems and leaf veins of plants which are severely stunted. Odontites spp.: Ditylenchus dipsaci

5a Systemically infected plants or shoots developing faster, rigidly erect. Leaves pale-green, narrowed, curved downwards at margin, arched; soon covered with a dense white down of branched conidiophores. O. litoralis, vulgaris: Plasmopara densa

5b Stem with thinner or thicker quill-like swellings, up to several cm long, blue-grey, at first closed, later on rupturing and dusty. Infestation sometimes as bulge-shaped sori encroaching onto leaves. O. lutea: Urocystis schizocaulon

6a Wart-shaped, multi-cellular galls on leaves and stems, less than 1 mm across, occasionally coalescing; nutritive cells with golden-yellow perennial sorus. O. verna: Synchytrium aureum

6b Complete plant disfigured. Shoot axis and leaves with rotund red warts, usually gregarious, up to 1 mm across. Perennial spores inside a single (rarely in 2–3) enlarged parenchyma cells. O. verna, vulgaris: Physoderma negeri

1a On vegetative plant parts => 3

1b In inflorescences or single flowers => 2

2a On inflorescence stalks or spikes. Inflorescence partially ± severely stunted and greened or bleached. Aceria tenuis

2b Single ovaries of a panicle strongly swollen and transformed into an oval or oblong smut body, up to 10 mm long; inside develop brown-black spore masses, at first clotted, later on crumbling and forming dust of spores. Neovossia moliniae

3a On above-ground parts => 4

3b Root hairs distinctly swollen; inducer inside the hair. Sorosphaerula radicalis

4a On culms => 5

4b Leaf sheath at base swollen, bellied out. Containing a large, whitish larva, almost 5 mm long. Unidentified gall midge

5a Culm with spindle-shaped or bellied swelling => 6

5b Shoot axis immediately above the ground below the leaf sheath with weak, slightly rimmed depression. Containing a single white larva. Mayetiola moliniae

6a Culm just above the ground swollen to bellied out, apically conically narrowed gall up to 10 mm long, which erupts from the leaf sheath. Larvae white, gregarious. Mayetiola ventricola

6b Culm weakly swollen, containing a single, orange-yellow larva almost 5 mm long. cf. Lasioptera moliniae

1a On parts above ground => 5

1b On roots => 2

2a Outside of root hardly changed, only disfigured inside or with rotund galls having central chamber => 4

2b Distinctly protruding galls, larval chamber absent => 3

3a Nodular galls, occupying all sides of root body. Lupinus spp.: Meloidogyne hapla

3b Main roots with protrusions up to about 15 mm long, broadly attached, usually many, often clumped close to root collar, coalescing, tuberculate, on perennial species even up to 50 mm wide; less often rotund or oblong-oval smaller nodules also on the adventitious roots. Lupinus spp.: Rhizobium lupini

4a Galls not recognisable from the outside; with giant cells inside. Lupinus spp.: Heterodera schachtii

4b Roots with rotund, 4–6 mm long gall with chamber containing beetle larva. L. luteus: Unknown snout beetle

5a Malformations of leaves, stems and flowers => 6

5b Pod disfigured, slightly atrophied; inner wall with mycelium. Containing a single larva. L. albus: Asphondylia lupini

6a Malformations caused by aphids => 7

6b Development of plant severely stunted; axial parts irregularly swollen, spongy. Infestation often encroaching onto stalk and venation of severely disfigured leaves. L. angustifolius: Ditylenchus dipsaci

7a Apterae are pale bluish-grey-green, dusted with white wax; body length 3.2‒5.1 mm. Alatae have a brown pterothorax. Lupinus spp.: Macrosiphum albifrons

7b Apterae and alatae black. Leaf blades distorted, also strongly curved, rolled or folded. L. angustifolius, luteus: Aphis fabae

1a On vegetative organs => 2

1b Flower buds inflated, thickened, unopened, usually normally coloured. Containing pale yellow larvae. L. vulgare: Placochela ligustri

1c Root with rounded or spindle-shaped swelling, 2–5 mm across; containing eelworms, some may be glistening white pear-shaped females with eggs. L. vulgare: Meloidogyne ardenensis

2a On leaves => 5

2b On buds or axial parts => 3

3a On axial parts => 4

3b Several axillary buds, rarely the apical bud, slightly swollen, stunted, developing leaves often only scale-like. Malformation resulting in compact, ± pyramidal witches’ broom-like structures. L. ovalifolium, vulgare: Aceria loewi and/or Aculus ligustri

4a Axial parts, mainly at base, with conspicuous proliferations, up to walnut-size, soon woody, irregularly wrinkled, on surface, dark-brown. “Bacterial cancer” L. vulgare: Agrobacterium tumefaciens

4b Bark swollen, with rimmed irregular depressions, containing causer. L. ovalifolium, vulgare: Chionaspis salicis

5a Malformation of many leaves at shoot tip => 6

5b Leaf blade with rotund, yellowish-green pads, sometimes slightly swollen if on venation, bearing cups on underside. L. ovalifolium, vulgare: Puccinia obtusata

6a Axis of young shoots and stalks of young leaves shortened. Infected leaves loosely clustered. Prociphilus bumeliae

6b xis of young shoots not shortened; usually deflected from the tip, bearing many, distant, downwardly rolled or slightly curved leaves, sometimes twisted, yellow- to rust-spotted. L. ovalifolium, vulgare: Myzus ligustri

1a On parts above ground => 3

1b On roots => 2

2a Rotund- to oblong-oval nodules, about 3 mm long laterally attached on main- and side-roots. L. culinaris, nigricans: Rhizobium leguminosarum

2b Outside of roots hardly disfigured, inside containing giant cells; bearing temporarily white to dark, about poppy seed- sized egg capsules (cysts). L. culinaris, nigricans: Heterodera schachtii

3a Leaflets of many terminal leaves rolled inwards and upwards, ± bent. L. culinaris, nigricans: Aceria trifolii

3b Flower bud swollen, unopened. L. culinaris: Contarinia sp.

= Early records of Dasineura viciae and Asphondylia ervi on “lentils’” need confirmation.

c Flower bud swollen, unopened. L. culinaris: Contarinia lentis

1a On vegetative plant parts => 2

1b Capitula deformed; receptacle thickened. Unidentified tephritid fly

= Midge larvae of an undescribed Dasineura occur in capitula of Mediterranean H. alpina

2a Leaf blade or petiole with galls caused by fungi, spores of which develop on the outside, or shine through the gall surface => 5

2b Malformation of the leaf blade by animal inducers => 3

3a Localised galls => 4

3b Leaf blade deflected ± curled, locally intense green. Philaenus spumarius

4a Leaf blade with pock-like swellings, which are especially arched on the underside. Unidentified gall mite

4b Leaf blade between the veins bulging and swollen. Larvae on the underside. Trioza thomasii

5a The fruiting bodies develop on the surface of spindle-shaped galls => 6

5b Wart-shaped, less than 1 mm long galls, the ± golden yellow spores develop inside and shine through the gall surface. Synchytrium vulgatum

6a Only just protruding, orange-coloured thickenings on petioles and on the underside of leaf veins bearing densely, ± circular arrangements of aecia and with pycnidia developing on the upperside. Uromyces veratri

6b Telia in small to extended brown sori. Stronger infestation sites on leaf blades with upperside impressions and with rotund, protruding, compact pads on underside; on veins and petioles developed as ± elongated spindle-shaped, often yellow margined bulges. Puccinia conglomerata

1a On above-ground parts => 2

1b Roots with almost rotund swellings, up to 4 mm long, sometimes clustered. H. annuus: Meloidogyne hapla

= Heterodera schachtii is known from H. annuus

2a Galls on root collar or on stem. The inducers are inside the galls => 4

2b Malformations predominantly on leaves. The inducers live on the surface of the malformations => 3

3a Leaves variously curled or bulging; malformations by aphids. Helianthus spp.:

a Brachycaudus helichrysi

b Aulacorthum solani

c Aphis fabae

3b Leaf blades of young plants over extensive parts and in various ways bent downwards, curled, and dark green close to the froth-covered nymph. Helianthus spp.: Philaenus spumarius

3c Dull white spots, pustules, even crusts on underside of leaves, largely consisting of a mass of conidia. H. annuus: Pustula helianthicola

4a Up to walnut- size or extensive, rugose proliferations on root collar or the basal stem parts. H. annuus, tuberosus, etc.: Agrobacterium tumefaciens

4b Spongy swellings of various shape on stems, petioles, leaf veins of young plants. H. annuus, tuberosus: Ditylenchus dipsaci

1a On above-ground plant parts => 2

1b Nodular swellings on roots. Meloidogyne hapla

2a On parts of inflorescence or on fruits => 6

2b On vegetative parts => 3

3a Malformations caused by animal parasites => 4

3b Stalks, midrib or veins of leaves, also stalk of umbel or fruit with bulging swellings bearing spermogonia and pale-yellow aecia. Uromyces graminis

4a Rosette leaves or terminal parts of vegetative shoots variously disfigured by aphids; midrib ± stunted and distorted; tips of leaflets clustered, curved and curled => 5

4b Globular swelling of ramification of leaflet; gall inside covered with mycelium. Containing a single gall midge larva. Lasioptera carophila

4c Midrib of leaf locally severely stunted and including some side spindles strongly converging downwards, nest-like. Philaenus spumarius

5a Aphid black. Aphis fabae

5b Aphid green. Cavariella aegopodii

6a Centre of umbel or stalk of umbel ± swollen, club-shaped. Inner wall covered with mycelium. Containing a single red larva. Lasioptera carophila

6b Spindle-shaped swelling of stalk of umbel. Containing a single yellow larva. Lasioptera umbelliferarum

= Lasioptera foeniculi has been described causing fruit galls. Galls from September up to November; larvae pupate in soil, adults emerge about 10 days afterwards.

6c ruit conspicuously swollen, ± reddened, often protruding above the partial umbel. Containing a single orange-red larva. Kiefferia pericarpiicola

1a Malformations of leaves at the tips of the shoots => 3

1b Swellings of the shoot stems => 2

2a Spindle-shaped or cylindrical swelling in main- or side stem near a node or in axils of flower peduncles, about 10–15 mm long, with round opening when mature; one or several yellowish-white caterpillars with a yellow-brown head, in pith with frass. Upper stem parts stunted, often conspicuously discoloured. Adaina microdactyla

2b Stem mainly close to the ground, with differently situated and expanded, sometimes curved swelling. A scale insect in a depression. Planchonia arabidis

3a Malformations by aphids or spittlebugs => 4

3b Leaves on stunted shoot tips clustered, rolled upwards, rudiments of inflorescences stunted. All infected parts conspicuously white pubescent. Aceria eupatorii

4a Aphid malformations => 5

4b Leaf segments nest-like converging, the leaf blades curled, dark green close to the froth-covered nymph. Philaenus spumarius

5a Leaves on ± stunted shoots more or less stunted, the margins curved downwards, the leaf blade ± curled. Aphid 1.5–2 mm long, bright yellowish to yellow green, with short conical yellowish to green cauda. Brachycaudus helichrysi

5b Similar malformations by dark green aphids; siphunculi and cauda dark to black. Aphis frangulae

1a On parts above ground => 2

1b Roots with ± expanded spindle-shaped, fleshy swellings, which contain densely crowded masses of minute spores in some cells. D. incana, muralis: Plasmodiophora brassicae

2a Malformations caused by fungi fructifying at surface of gall => 6

2b Malformations caused by animals, or by fungi fructifying inside galls => 3

3a Galls localised => 4

3b Infected shoots extensively disfigured, phyllanthy; leaves shorter and broader, ± disfigured; flowers often accumulated, tuft-like, atrophied or ± greened. D. aizoides, daurica, incana, muralis, nivalis, “rupestris”: Aceria drabae

3c On the same hosts and other Draba species in similar malformations. D. aizoides, daurica: Cecidophyes borealis

4a On leaves or stem parts => 5

4b Diseased shoots slightly swollen, slightly shorter than healthy ones; young seed soon distorted and filled with yellowish- to grey-violet sori. D. aizoides, alpina, incana: Thecaphora thlaspeos

5a Galls hardly 1 mm across but conspicuous, ± golden-yellow translucent; on leaves, stalks and even bracts; often coalescing into crusts. D. aizoides: Synchytrium drabae

5b Stalk of inflorescence shortened at tip, slightly thickened, curved. D. muralis: Cause unknown – ? dipteran

6a At first glossy, porcelain-like, with mealy dusty bulges on all green parts after rupturing. D. aizoides, cuspidata, hispanica, incana, sauteri: Albugo candida

6b Infected organs, mainly the upper stem parts, variously ± bulge-like, swollen and disfigured. Draba spp.: Puccinia drabae

6a Shoots etiolated. Underside of leaves often bearing dense, rotund sori. D. cinerea, daurica: Puccinia thlaspeos

6b Leaves with pales spots. Underside with a dense white down, consisting of erect conidiophores that apically are branching several times, each branch ending in a conidium. D. muralis, nemorosa: Hyaloperonospora drabae

6a Similar malformation. D. daurica, nemorosa: Hyaloperonospora norvegica

1a Leaf blades arched and curled, caused by aphids or cercopids => 3

1b On root collar or roots => 2

2a Roots with small nodule-shaped swellings. Meloidogyne hapla

2b Conspicuous succulent, cauliflower-shaped proliferations on tubers, on root collar or stem base. Agrobacterium tumefaciens

2c Irregular proliferations of the stem base, combined with an abundant development of buds. Rhodococcus fascians

2d Extensive malformations usually accompanied by R. fascians. Aphelenchoides fragariae

3a Deformities caused by aphids => 4

3b nfected young shoots severely stunted, the leaves curved downwards, curled, dark green close to the froth-covered nymph. Philaenus spumarius

4a Aphid black. Aphis fabae

4b Aphid green. Aulacorthum solani

1a Malformations on leaves => 3

1b Malformations on stems => 2

2a Witches’ broom-like malformations with only little, often reddish leaves on sap-rich, whip-shaped shoots. C. speciosa: Inducer unknown, presumably caused by a fungus, Exoascaceae

2b Considerable cancer-like proliferations on basal stems. C. speciosa: Agrobacterium tumefaciens

3a Malformations on several terminal leaves caused by aphids => 4

3b Leaves with ± protruding bladder-like, pale-green or reddened swellings, later on withering, which at maturity are occupied by a grey-white layer of fungal asci. ? C. speciosa: Taphrina bullata

4a Leaves rolled inwards and crumpled, clustered nest-like on the ± shortened shoots => 5

4b Leaves obliquely bent downwards and ± rolled. C. japonica: Myzus persicae

5a Aphid with rather long siphunculi. Chaenomeles spp.: Aphis pomi

5b Aphid with short, thick, green siphunculi. C. japonica, speciosa: Rhopalosiphum oxyacanthae

1a On inflorescences or flowerd => 7

1b On vegetative plant parts => 2

2a Leaves with long stripes caused by smuts => 6

2b Malformations caused by animal parasites => 3

2c Whitish, at surface yellowish or brownish patches, which envelope a large area of the upper part of stem, of which further development is stunted. Node of stem rarely swollen, encircled by fungus stroma, yellowish when mature; several nodes may be affected; flowering stunted; stroma contains narrow asci and filamentous spores. Brachypodium spp.: Epichloë sylvatica

3a Localised galls on culms => 5

3b Shoot tip with tuft-like clustering of leaves or complete plant disfigured => 4

4a Especially the tips of subterranean runners with short sheath-like, tuft-like accumulated leaves. Gall up to 40 mm long and 12 mm broad. Larva white with black buccal skeleton. B. pinnatum, sylvaticum: Unidentified chloropid fly

4b Tip of above-ground shoot with spindle-shaped tuft of leaves. Inside a larva causing a severely stunted, broadened culm. B. pinnatum, sylvaticum: Tetramesa brachypodii

5a Stem closely just above a node with 10–12 mm long and 4–5 mm broad, saddle-like depression, thickened at both ends, containing a white larva. Usually ± enclosed by leaf sheaths. B. pinnatum, sylvaticum: Mayetiola hellwigi

5b Culm above one of the lower nodes with an egg-shaped swelling about wheat grain size. Containing a single larva. B. sylvaticum: Tetramesa sp.

6a Often all parts of host diseased, exceedingly leafy; initially developing faster, soon severely stunted, remaining small and sterile. Leaves with long, at first slightly arched patches of smut, then breaking open, ± fraying out the leaves, releasing a black-brown mass of spores. B. pinnatum, retusum, rupestre, sylvaticum: Tilletia olida

6b Similar stripes of smut on the leaf blades of often further developed, hardly additionally leafed plants. Spores rotund to oblong-oval, with many blunt warts. B. pinnatum, sylvaticum: Ustilago striiformis

6c Long conspicuous stripes on chlorotic leaf tissue caused by rust fungus. B. pinnatum, sylvaticum: Puccinia striiformis

7a Spikelets elongated; flowers ± greened, bleached if strongly infected. B. pinnatum: Aceria tenuis

7b lowers leafy; glumes ± enlarged, occasionally enclosed in the spikelet; the midrib bent zig-zag-like. B. pinnatum: ? Ditylenchus sp.

7c Complete plant stunted by scale insects, especially the inflorescence. B. pinnatum, retusum, rupestre, sylvaticum: Eriopeltis festucae

1a On A. officinalis => 2

1b On A. acutifolius, aphyllus. Young twigs irregularly swollen and curved, terminally with tufts of compressed leaves with broadened bases, discoloured or reddish. Overwintering buds variously abnormally hypertrophied. Containing flesh-coloured larvae: Dasineura turionum

1c Usually the whole shoot, just after budding, is transformed into a gall. Leaf scales are swollen and broadened at base. The white midge larvae are located under the swollen scales. A. acutifolius, albus, tenuifolius: Dasineura minardii

1d Fruits changed into spongy mass. A. aphyllus: Dasineura sp.

2a On above-ground parts => 3

2b Roots with nodular swellings. A. officinalis: Meloidogyne hapla

3a On vegetative parts => 4

3b Flower buds globular, perianth succulent, swollen, dark-green; not opening. Containing several white- to orange larvae. A. officinalis: Contarinia florum

4a Stunting of stems with terminal green shoots; caused by aphids => 5

4b Stem of young, pale or greened shoots crippled. Tip ± curved, crooked, dying off early. Often several yellowish-white larvae, up to 10 mm long in extended tunnels. A. officinalis: Plioreocepta poeciloptera

4c Terminally distorted and discoloured spines of young twigs transformed into swellings with broadened base. Gregarious white larvae between the spines. A. acutifolius, aphyllus, officinalis: Dasineura asparagi

5a Leaves of solitary or of several neighbouring shoot tips accumulated densely like bottle brushes, shortened, ± rounded, rigid, dark green; with colonies of grey-powdered aphids in between. A. aethiopicus, densiflorus, officinalis: Brachycorynella asparagi

5b Similar malformations; however more loosely tuft-like; leaves softer, ± downwardly deflected. Aphid black. Asparagus spp.: Aphis fabae

1a On parts above ground => 2

1b On roots or on root collar. Nodular swellings on roots. Galls partially with side roots. Antirrhinum spp.: Meloidogyne hapla

2a On leaves => 3

2b Swelling of stem. A. latifolium, majus: Mesoscyonyx sicardi

2c Capsule slightly swollen and disfigured; a single or several beetle larvae inside. A. majus: Rhinusa antirrhini and/or Rhinusa neta

3a Leaves ± curled and margins deflected; bearing aphids on underside => 4

3b Leaves stunted on shortened shoot tips, pale green, deflected over tip and margins, brittle, appearing slightly thickened; with down of branched conidiophores on underside. A. hispanicum, majus, sempervirens: Peronospora antirrhini

4a Leaf blades strongly curled. Antirrhinum spp.: Aulacorthum solani

4b Leaf blades spoon-like arched, curled, ± discoloured, bearing aphids on underside. A. barrelieri: Myzus persicae

1a On buds and shoot axis => 6

1b On leaves (or occasionally fruits for fungi) => 2

2a Galls ± bulge-shaped, usually yellowish, with patches of spores on upper side => 5

2b Malformations caused by animals => 3

3a Galled leaves not conspicuously clustered => 4

3b Terminal leaves clustered. A. ovalis: Dysaphis parasorbi

3c Leaves terminal on severely stunted shoots mainly on tip rolled downwards, usually densely clustered. Amelanchier spp.: Aphis pomi

3d Shoots with several leaves ± curved and variously obliquely downwardly curved along the midrib. Amelanchier spp.: Rhopalosiphum oxyacanthae

4a Leaf blade ± pod-like folded upwards along the midrib, thickened in the middle. A. ovalis: Unidentified gall midge

4b Leaf blade with many pocks, protruding on both sides of leaf. A. ovalis: Eriophyes aroniae

5a Leaves, sometimes also young shoots, with yellow, later on reddened in the middle, swollen, aecia bearing pads. Peridium cylindrical, 2–3 mm long, open above, deeply thread-like lacerate; lateral walls of cells with many tubercles of various shape and size. Amelanchier spp.: Gymnosporangium clavariiforme

5b Galls similar. Peridium usually oblong-cornicular, 3–4 mm long, conical apex, at first closed, then opening, slightly or not lacerate at margin; lateral walls of cells ± densely tuberculate, or very short, with obliquely running ridges. A. ovalis, asiatica: Gymnosporangium cornutum

6a On shoot axial parts => 7

6b Buds swollen, not opening; scales enlarged, thickened, densely white pubescent. A. ovalis: Eriophyes amelancheus

7a Bark of stems or branches with cracked cancer-like proliferations; with white powdered aphids in cracks. Amelanchier spp.: Eriosoma lanigerum

7b Major branches with spindle-shaped swellings. A. ovalis: Viscum album

1a On parts above ground => 3

1b On roots => 2

2a Side roots with mainly rounded, nodular swellings. Althaea officinalis; Alcea rosea & var. nigra: Meloidogyne hapla

2b Main root thickened, beet-like. Central chamber contains a single larva. Althaea hirsuta: Unidentified coleopteran

3a Malformations caused by animal parasites => 4

3b Leaves and all other green organs, as well as stem, epicalyx and even young ovaries, with rotund, 1‒2 mm broad, cushion-shaped swellings, soon bearing at first yellow-red, later on brown telia. Telia germinating immediately, giving them a whitish-powdery appearance. Alcea spp.; Althaea spp.: Puccinia malvacearum

4a Malformations lacking conspicuous additional pubescence => 5

4b Leaves on Althaea officinalis with localised erinea. Unidentified gall mit

5a Malformation of leaf blades => 6

5b A single mericarp contains a beetle; there also pupation takes place. Infected flowers fade prematurely. Alcea dissecta, rosea, setosa: Rhopalapion longirostre

6a Leaf blades, usually of many terminal leaves, on ± stunted shoots loosely arched downwards and ± curled. Alcea biennis, nudiflora, rosea; Althaea officinalis: Aphis althaeae

6b Leaf blade ± strongly wrinkled, margins deflected. Sometimes the flower buds are also disfigured. Contain pale green aphids with siphunculi half as long or equalling cauda. Alcea rosea, Althaea officinalis, cannabina: Acyrthosiphon malvae

6c Venation close to infestation stunted and deflected; neighbouring leaf blade part curled, deep green, rolled- or curved downwards, nest-like. Contains a froth-covered nymph. Alcea spp.; Althaea spp.: Philaenus spumarius

1a On vegetative organs => 2

1b Anthers in rarely disfigured flowers temporarily swollen; later filled with black-violet spores. Microbotryum violaceum

2a Malformations with surface fruiting fungi, at least temporarily => 5

2b Malformations caused by animals => 3

3a Malformations on stems or leaves of ± developed plants => 4

3b Young plants severely stunted; especially the basal parts swollen, spongy. Swellings pale green, undulate at surface. Ditylenchus dipsaci

4a Stem with localised swellings. Unidentified lepidopteran

4b Tuft-like accumulation of basally strongly pubescent leaves. Inducer unknown

4c Stem stunted locally, one or two neighbouring leaves strongly rolled over their tips; close to the froth-covered nymph undulate, deep-green. Philaenus spumarius

5a Leaves on underside with rotund, ring-shaped or sometimes oblong compact crusts of coalescing sori on slightly swollen bulges; at first bearing pale, later on with black-brown telia. Bulges also developing on calyx teeth and stems. Puccinia arenariae

5b Leaves and stems with yellowish, ± swollen spots; diseased leaf blades, and even the corolla, often characteristically curled; sori ± grey frosted when asci are mature. Taphrina githaginis

1a On stems or leaves => 2

1b Centre of umbel or stalk of umbel ± swollen, club-shaped. Inner wall covered with mycelium. Contains a red larva. Lasioptera carophila

2a Large parts of plant disfigured => 4

2b Stem or leaves with localised galls => 3

3a Stem, and stalks of partial umbels with lateral rounded swellings, 2–3 mm long; with an irregular larval chamber inside. Unidentified beetle

3b Minor, weak bulge-like archings on leaf veins, rachis, -stalk or stem; soon bearing spermogonia and primary uredinia. Puccinia nitida

4a Curled leaf blades caused by aphids or cercopids => 5

4b Younger plants severely stunted. Leaf axis and possibly basal stem parts distinctly shortened, spongy, pale-green, with undulate-wrinkled surface. Ditylenchus dipsaci

5a Larger composite leaves ± nest-like or bell-shaped converged downwards; strongly curled, deep-green close to the froth-covered nymph. On developing plants often several leaves on locally markedly shortened stems are similarly disfigured. Philaenus spumarius

5b Leaves remaining small, rolled, closely accumulated, dark-green discoloured; bearing green aphids. Cavariella aegopodii and/or C. pastinacae

= Also living in summer on several umbellifers is the aphid Hyadaphis foeniculi which might be responsible for the malformations

5c Several leaves stunted and curled; tips deflected. Leaf blades ± knobby swollen, not discoloured. On underside several flat froth-covered nymphs surrounded by a border of white wax hairs. Trioza apicalis

2a Expanded or locally narrowly confined malformations caused by animal inducers => 5

2b Bulge-like swellings on leaf venation, -stalk or young stem parts, caused by fungi => 3

3a Conspicuous, often ± curved swellings, bearing uredinia or telia => 4

3b Bulges of various size on ± curved leaf blades and axis, bearing yellowish spermogonia and aecia. S. carvifolia: Puccinia bistortae

3c Vitreous bulges. S. carvifolia: Protomyces macrosporus

3d Leaves on the underside a white fungal down of erect conidiophores that apically bear a few short branches, each one ending in an ovoid conidium. S. carvifolia: Plasmopara selini

4a Fungus develops only 3-celled teliospores bearing distal spines. S. carvifolia: Nyssopsora echinata

4b Sometimes up to 30 mm long sori coalescing into ± protruding bulges on stems are induced by a mycelium developing primary uredinia and spermogonia. Teliospores 2-celled. S. carvifolia: Puccinia selini-carvifoliae

5a Malformations caused by aphids, spittlebugs or mites => 6

5b Centre of umbel or stalk of umbel ± swollen, club-shaped. Inner wall covered with mycelium. Containing a red larva. S. carvifolia: Lasioptera carophila

6a Malformations caused by aphids or spittlebugs => 7

6b Complete plant variously stunted. Young stems ± distorted. Umbels stunted; flowers ± greened or leafy. S. carvifolia, dubium, silaifolium: Aceria peucedani

7a Leaflets converging, axis ± deflected, leaf blades curled, wrinkled and deep green at site of infestation. S. carvifolia: Philaenus spumarius

7b Stalks of umbel, sometimes in the same umbel, variously shortened. Flowers clustered; the severely stunted organs sometimes variously greened or also leafy. S. carvifolia: Unidentified aphid

1a On leaves or flowers => 2

1b Conspicuous, at first whitish, succulent, later on strongly browned, woody proliferations on root collar. Rhododendron spp.: Agrobacterium tumefaciens

2a On shoot tips or leaves => 3

2b The flowers are irregularly ± double. R. ferrugineum, hirsutum, intermedium: Aceria alpestris

3a Malformations of leaf blades => 5

3b Malformations of shoot tips => 4

4a Conspicuous bud-like tuft of leaves on shoot tip. R. ferrugineum: Dasineura rhododendri

4b Terminal buds crippled; often increased in number. Leaves reduced and disfigured. Buds dying prematurely. ‘Shoot tip mite’. R. simsii: Tarsonemus sp.

5a Leaf blade with rolls of margin or pouch-like to spherical galls => 6

5b Leaf blade otherwise weakly disfigured. R. ferrugineum, hirsutum: Cacopsylla rhododendri

6a Roll of leaf margin => 8/p>

6b Succulent galls on leaf blade => 7

7a Leaf blade largely or completely thickened, pale-green, later on densely chalk-white frosted, especially on underside. Sometimes several, almost rosette-like clustered leaves terminally on severely stunted, thickened, young shoots similarly disfigured; galls sometimes also on calyx leaves and even on corolla. “Earlobe disease”. R. caucasicum, indicum, nudiflorum, obtusum: Exobasidium japonicum

7b Up to about cherry-size, succulent, yellowish or often one-sided reddened, later on white frosted, often almost globular galls on leaves, sporadically even on flower parts, as well, sometimes, ± clustered, raceme-like, on shoot tips. R. ferrugineum, hirsutum, x intermedium: Exobasidium rhododendri

7c Galls succulent red-orange. R. luteum, ponticum: Exobasidium horváthianum

8a Leaves on unshortened shoot tip usually narrowly rolled upwards over all their length, lighter; with small 1-celled hairs on both sides. R. ferrugineum, hirsutum, intermedium: Aceria alpestris

8b Leaf margin rolled downwards, ± curled and crippled. R. indicum, molle: Phyllocoptes azaleae

8c Mites living in buds and free on the underside of the leaves. They can cause bronzing and rusting of the young leaves, downwards rolling of the leaf margins and eventually stunting; in nurseries. R. atlanticum, japonicum: Aculus atlantazaleae

8d Rolling of the leaf margin. R. ferrugineum: Aculus thomasi

1a On roots or on root collar => 5

1b On parts above ground => 2

2a Malformations on vegetative parts => 3

2b nflorescence ± half-globularly clustered as result of shortening of axis. Development of flowers stunted, usually unopened. P. paniculata: Unidentified dipteran

3a Causers on outside of malformations => 4

3b Single or all shoots of a plant strongly shortened by eelworms living inside the tissue, variously swollen, leaves ± curved and curled, partially strongly reduced, narrowed, almost thread-like. Shoot tuft- to broom-like. P. amoena, paniculata, etc.: Ditylenchus dipsaci

4a Leaves strongly rolled and curled over their tips, locally deep green. Phlox spp.: Philaenus spumarius

4b Malformations of leaf blades caused by aphids. P. paniculata: Unidentified aphid

5a On root collar => 6

5b Roots with small swellings bearing several side roots. P. paniculata, etc.: Meloidogyne hapla

6a Considerable proliferations with only small partitioned surface. P. paniculata: Agrobacterium tumefaciens

6b Clustering of crook-backed branched, markedly shortened, fleshy thickened shoots. P. paniculata, etc.: Rhodococcus fascians

1a On vegetative parts => 2

1b Corolla unopened, lower part thickened, leather-like, colourless to brown, up to 4 mm long, 2 mm broad; not joined with the slightly swollen calyx. Containing a single larva. O. vulgare: Asphondylia hornigi

2a Malformations of undefined shape on several organs, mainly at tips of shoots => 4

2b Galls on shoot tips, as well as lateral buds or on axial parts of shoots => 3

3a Shoot axis with spindle-shaped or oblong, bulging, multi-chambered swelling. O. vulgare: Thamnurgus kaltenbachii

3b Small, unilateral stem galls, containing a weevil larva or its pupa. O. vulgare: Squamapion origani

3c Shoot tip or lateral buds transformed into oval tufts of leaves, up to 15 mm long and 10 mm broad, greenish, compact. Leaves broadened, thickened, arched, on upperside often with long white hairs. Containing several red larvae. O. compactum, vulgare & subsp. virens: Blastomyia origani

4a Malformations caused by animals => 5

4b Large parts of plant or only single shoots transformed into little, rigid, erect witches’ brooms as result of excessive branching and leafiness. Diseased shoot axis distinctly narrowed; leaves conspicuously reduced. Brownish sori soon develop on axial parts. O. vulgare: Puccinia thymi

4c Leaf blades, especially of young leaves at shoot tip, with thick purple patches bearing spermogonia and aecia, followed by uredinia and telia. O. vulgare & subsp. virens: Puccinia menthae

5a Malformations lacking excessive pubescence => 6

5b Tip of non-flowering or flowering shoots disfigured; developing ± dense masses of felt-like pubescent leaves, and leafy or greened flowers. O. majorana, vulgare: Aceria labiatiflorae

6a Galls caused by aphids => 8

6b Galls caused by gall midges or spittlebugs => 7

7a Roll of leaf margin caused by gall midge larvae. O. vulgare: Unidentified gall midge

7b Shoot axis buckled, bent locally, bearing several deflected, curled, partially deep green leaves. O. vulgare: Philaenus spumarius

8a Several to many leaves at the end of shoots apically increasingly stunted, laterally ± narrowly rolled, curled. Plants often largely disfigured. O. majorana, vulgare & subspp. gracile + virens + viridulum: Aphis origani

8b Leaves curled. O. vulgare: Aphis nepetae

8c Malformations caused by aphids on terminal vegetative- or developing flowering shoots. O. majorana: Myzus ornatus

1a On parts above ground => 2

1b Roots with nodular swellings. N. cataria: Meloidogyne hapla

2a On flowers or fruits => 6

2b On vegetative organs => 3

3a On leaves => 5

3b On shoot tips or axial parts => 4

4a Tip of shoot ± disfigured. Youngest leaves erect, folded together, yellowish with cartilaginously rolled margin. Containing orange-yellow larvae. N. cataria: Wachtliella stachydis

= Midge described from Stachys, on which it also induces inflorescence galls. Identity of the midge on Nepeta is doubtful

4b Shoot axis with multi-chambered, elongate and bulging swellings, up to 30 mm long. In each chamber is a single, curved, lemon-yellow beetle larva. N. cataria: Squamapion vicinum

5a Leaves curled or loosely rolled. N. cataria, nepetella & subsp. aragonensis, nuda: Aphis nepetae

5b Leaves folded or rolled. N. cataria: Aulacorthum solani

6a Gall on flowers => 7

6b One mericarp transformed into a ± globular gall, up to 5 mm long, the three remaining ones aborted. Calyx enlarged, cup- or bell-shaped, later on rupturing over its length. Corolla atrophied. Containing a single larva. N. nuda, also N. beltranii, cataria, grandiflora, latifolia, nuda & subsp. albiflora, ucranica & subsp. parviflora: Liposthenes kerneri

7a Flowers swollen at base, disfigured, often unopened. Containing red larvae. N. cataria: Jaapiella catariae

7b Flower buds swollen, egg-shaped, dark-green, unopened. N. nuda: Asphondylia sp.

1a On parts above ground => 2

1b Root with nodular swellings. M. sylvestris: Meloidogyne hapla

2a Malformations on vegetative parts, only sometimes encroaching onto primordia of inflorescences => 3

2b Single mericarps between the other hardly changed mericarps conspicuously swollen, up to twice the normal size. Containing a curved beetle larva. M. alcea, multiflora, neglecta, pusilla, subovata, sylvestris, trimestris: Malvapion malvae

3a Expanded malformations of leaves caused by animals => 5

3b Localised galls on stems or small pads bearing sori on all green organs => 4

4a Leaf blades, -stalks, axial parts of shoots, even calyx and green fruits with many small, rotund or oblong, yellowish, eventually red- to dark brown spores bearing bulges. Malva spp.: Puccinia malvacearum

4b Plant ± atrophied; stem thickened, distorted; inner wall browned. M. moschata: Inducer unknown

5a Malformations with abnormal pubescence; caused by mites => 8

5b Malformations lacking abnormal pubescence; caused by aphids, scale insects or spittlebugs => 6

6a Malformations contain aphids => 7

6b Shoot axis often with several oval to spindle-shaped swellings with centrally rimmed depressions which contain a flat froth-covered nymph. M. thuringiaca: Planchonia arabidis

6c eaves curled, deflected, nest-like; often deep green at infestation site. Infestation on erect young plants usually similarly involving several leaves. Containing a froth-covered nymph. Malva spp.: Philaenus spumarius

7a Leaf margin deflected or rolled downwards. Leaf blade variously curled to undulate, sometimes arched, umbrella-like. Infestation often on terminal leaves. Aphids green. Malva spp.: Aphis umbrella

7b Similar, less conspicuous malformations caused by black aphids. M. neglecta, sylvestris: Aphis fabae

7c Leaf blade wrinkled. M. neglecta, sylvestris, thuringiaca: Aphis althaeae

7d Leaf blade ± strongly wrinkled, margins deflected. Containing pale green aphids with siphunculi half as long as to equalling cauda. M. neglecta, parviflora, pusilla, sylvestris, thuringiaca, trimestris: Acyrthosiphon malvae

8a Shoot tip stunted. Leaf blade variously disfigured and atrophied, ± thickened, rolled inwards, curled or undulate and excessively haired; often yellowing prematurely. M. alcea, moschata, thuringiaca: Aceria gymnoprocta

8b Segments of older leaves ± converging and disfigured, bag-like; usually on leaf underside on the thickened veins with dense, yellowish, felt-like pubescence. Younger leaves, densely clustered at shoot tips, similarly but more severely disfigured, often haired on both sides. Erinea also on petioles, shoot axis and calyx. M. alcea, moschata, thuringiaca: Aceria gymnoprocta

1a On flowers => 8

1b On vegetative plant parts => 2

2a On shoot tips or on many terminal leaves => 5

2b Galls on leaf blade or malformation of a few leaves at any point of insertion => 3

3a Wart- or spindle-shaped galls on leaf blades, occasionally on stems => 4

3b Usually several ± nest-like clustered, deflected, curled, locally deep green leaves on one-sided stunted axial parts. Philaenus spumarius

4a Yellowish, multi-cellular warts, less than 1 mm long, occasionally coalescing into crusts or ridges. Also on lower stem parts. Synchytrium aureum

4b Leaf blades with sori up to about 5 mm long, rotund, sometimes slightly arched on underside on usually yellow-green spots or spindle-shaped weak bulges on leaf veins, -stalks and stems; eventually covered by dark-brown sori. Puccinia arenariae

5a Malformations of shoot tips => 7

5b Malformation of complete shoots, or of many leaves on shoot tips => 6

6a Diseased complete shoots develop ± rigidly erect, internodes elongated; the bleached leaves ± stunted and bearing loose yellow sori on underside.
Melampsorella caryophyllacearum

6b Leaves on apically progressively shortened stems ± twisted and curled, the halves bent upwards. Brachycolus stellariae

7a One-, occasionally also two outer leaf pairs inserted on terminal or lateral shoots stunted, pale, basally thickened, converging, transformed into an erect, ± conical gall. Containing several pale- to lemon-yellow larvae. cf. Macrolabis stellariae

= Also a gall associated with disfigured flowers might be caused by this midge

7b Strongly clustered, tuft-like accumulation of stunted, upwardly rolled and bulging leaves. Brachycolus stellariae

8a Flowers greened or leafy. Cause unknown – ? gall mite

8b Anthers in hardly disfigured flowers temporarily swollen; later on filled with dark-violet spores. Microbotryum stellariae

1a On shoot parts => 2

1b Roots with nodular swellings. L. usatissimum: Meloidogyne hapla

2a On shoot tips or flowers => 4

2b On leaves or stems mainly of young plants => 3

3a Weak swellings bearing pale yellow spermogonia and orange aecia on cotyledons or young stems. Linum spp.: Melampsora liniperda

= On L. catharticum lives Melampsora lini

3b Young plants largely disfigured, excessively leafy, shoots thickened basally, sometimes ± curved. Leaves clustered, undulate, ± swollen and twisted. Occasionally localised, ± irregular, spongy, pale green swellings also on higher inserted, stunted stem parts and leaves of further developing plants. L. usitatissimum, tenuifolium: Ditylenchus dipsaci

4a On shoot tips or terminal shoots => 5

4b Greened flowers on ± stunted plants. L. catharticum: Unidentified gall mite

= The gall midge Contarinia lini is galling flower buds of L. austriacum

5a Terminal leaves widened, keel-like, making a larval chamber, about 8 x 4 mm long, containing a single larva. Neighbouring leaves ± disfigured and clustered, rosette-like. L. alpinum, austriacum, bienne, catharticum, tenuifolium, usitatissimum: Dasineura sampaina

5b Variously disfigured, pale leaves clustered on shoot tips of distorted plants. L. usitatissimum: Thrips linarius and/or Th. angusticeps

1a On vegetative plant parts => 2

1b Ovaries transformed into a purple-violet gall up to 3 mm long and 1 mm thick gall. K. glauca, pyramidata: Anguina agrostis

2a Locally restricted or expanded malformations on culms and leaves => 3

2b Complete plant disfigured. Shoots of undeveloped plants stunted and ± spongy, swollen. Leaves ± stunted, partially disfigured. K. pyramidata: Ditylenchus dipsaci

3a Only on leaves => 7

3b Only on culms or on their tips => 4

4a Locally restricted galls on the internodes => 5

4b Shoot axis markedly shortened. Development of leaves ± stunted, accumulated into a loose tuft, the outer ones shorter than the inner ones. K. glauca: Unidentified chloropid fly

5a Galls on higher internodes => 6

5b Long spindle-shaped swelling at the base of the culm. Containing a single larva. K. glauca, pyramidata: Tetramesa schlechtendali

6a Sharply shouldered swelling, up to 12 mm long and 4 mm thick. K. pyramidata: Tetramesa sp.

6b Weak swelling, hardly protruding, 1–2 cm above the upper node. K. glauca, pyramidata: Tetramesa sp.

7a Leaf blades, occasionally also the sheaths, with elongated, parallel narrow bulges, at first grey translucent, then with dusting of spores. K. pyramidata: Tilletia sterilis

7b Similar sori. Spore mass black. Spores irregular globular to rotund oval, 10–15 x 8–11 µm. Wall densely covered with short, blunt warts. K. glauca, pyramidata: Ustilago striiformis

1a On parts above ground => 2

1b Broad spindle-shaped to globular fleshy galls on roots, also variously coalescing. I. balsamina: Meloidogyne hapla

2a On leaves or flowers => 4

2b On stems => 3

3a Mainly basal stem part with considerable, fleshy proliferations. I. balsamina, noli-tangere: Agrobacterium tumefaciens

3b Stem, also petioles, weakly to moderately swollen over a length of 5–100 mm, often variously distorted and densely covered with aecia. I. amphorata, balsamina, capensis, firmula, parviflora, scabrida, sodenii; not on I. noli-tangere: Puccinia komarovii

4a On leaves or cotyledons => 5

4b Flower buds swollen, small and unopened. I. noli-tangere: Unidentified gall midge

4c On flower stalks. I. noli-tangere: Semiaphis noli-tangere

5a On leaves => 6

5b The usually completely diseased cotyledons are paler than the healthy ones, often weakly spoon-like, arched upwards; on underside with whitish-grey down of branched conidiophores. I. balsamina, ?capensis, noli-tangere, walleriana: Plasmopara obducens

6a Leaf blade curled and ± strongly curved => 7

6b Leaf blade with rotund, almost bladder-like swellings. I. noli-tangere: Trioza sp.

7a Malformations caused by aphids => 8

7b Leaf blade deflected, strongly curled, especially close to infestation, often deep green; also clustering, nest-like, of all reduced parts, bulging, ± curved and twisted terminal leaves. Impatiens spp.: Philaenus spumarius

8a Apterae are bright green, pink or red, with extensive shiny brown-black dorsal shield, black siphunculi and yellow to whitish cauda; body length 2.1‒3.1 mm. On undersides of leaves along main veins, and later in dense colonies on flower stalks, of Impatiens spp., especially I. balsamina, balfourii, glandulifera, parviflora: Impatientinum asiaticum

8b Apterae are green with an extensive shiny black dorsal shield, black siphunculi and a pale cauda; body length 2.0‒2.7 mm. Singly or in small colonies on undersides of leaves of Impatiens spp. but especially associated with I. noli-tangere: Impatientinum balsamines

8c Leaf blade ± discoloured, curled and marginally ± deflected by black aphids. I. balsamina, glandulifera, parviflora: Aphis fabae

1a On parts above ground => 5

1b On root collar or on roots => 2

2a On main- or side roots => 3

2b Up to 8 mm long, almost globular, fleshy gall on root collar. Containing a single larva in a central chamber. I. amara: Ceutorhynchus assimilis

3a Short nodular or long cylindrical galls => 4

3b Outside of roots little changed, temporarily bearing white to brown, poppy seed sized cysts. Giant cells develop inside. I. amara, umbellata: Heterodera schachtii

4a Nodular to spindle-shaped galls, a few mm long, mainly on side roots. I. sempervirens: Meloidogyne hapla

4b Up to several cm long spindle-shaped to cylindrical, fleshy galls, usually on side roots. Iberis spp.: Plasmodiophora brassicae

5a On stems and leaves => 6

5b Flower buds swollen, unopened. I. sempervirens: Unidentified gall midge

6a Stem slightly stunted, with ± discoloured leaves, folded upwards, usually additionally curled. I. sempervirens: Brevicoryne brassicae

6b Glossy white, later on with mealy dusting, ± bulging swelling additionally usually slightly curved young axial parts or midribs of leaves. Also rotund dusty pads, in many Iberis species with violet-red margin, on yellowing leaf blades enclosed by a “chlorophyll isle”, on underside. I. amara, carnosa, “pruittii”, umbellata: Albugo candida

6c Upperside of the leaves with yellowish spots. Their underside with a white down, consisting of erect conidiophores that apically are dichotomously branching several times, each branch ending in a conidium. I. amara, gibraltarica, “pruitti”, saxatilis, sempervirens: Hyaloperonospora iberidis

1a On parts above ground => 2

1b Main- or side roots with conspicuous swellings, usually more than 5 mm long, spindle-shaped to cylindrical, succulent, compact. H. incana: Plasmodiophora brassicae

1c Much smaller swellings, only 3–4 mm long. H. incana: Meloidogyne hapla

2a On shoot tips, leaves, flowers or fruits => 4

2b On stems, petioles or midrib => 3

3a White sori of variable size, at first closed and glossy, porcelain-like, later with mealy dusting after rupturing, on ± swollen and disfigured green parts. H. incana: Albugo candida

3b Midrib of leaf or stem with swellings 12–15 (20) mm long, also deep green inside, one-chambered, spindle-shaped. Containing a single larva. H. incana: Ceutorhynchus chalybaeus

4a On flowers => 6

4b On shoot tips or leaves => 5

4c Silique swollen, containing a single orange midge larva. H. incana: Asphondylia stefanii

5a Axis, especially of developing axillary buds, severely stunted, between the bases of clustered leaves, especially at thickened bases, are several whitish to lemon-yellow jumping larvae. H. incana (incl. adpressa): Contarinia nasturtii

5b Leaf blades of young rosette leaves in variable expansion rolled upwards undulate or bent, usually pale green. Older leaves with variously expanded pale green, often deflected, folds. On upper side or underside in the galls are colonies of mealy dusted aphids H. incana: Brevicoryne brassicae

6a Flowers swollen, unopened; calyx enlarged, corolla and anthers necrotic; anthers and ovaries stunted and thickened. Midge galls => 7

6b Flowers conspicuously disfigured; calyx and corolla strongly enlarged, thickened and greened; stamens ± aborted; ovaries swollen, wide tube-shaped; partially with white sori, at first glossy, porcelain-like, later on with mealy dusting. H. incana: Albugo candida

7a Larvae with several, whitish- to lemon yellow, jumping. H. incana: Contarinia nasturtii

7b Several larvae, non-jumping when mature. H. incana: Gephyraulus raphanistri

7c Silique swollen, containing a single orange midge larva. H. incana: Asphondylia stefanii

1a Malformations caused by fungi with erupting or clearly transparent sori => 4

1b Malformations caused by animal inducers or fungi with fruiting bodies which are not apparent externally => 2

2a Pustule-shaped or minor bulge-like swellings on stems and leaves => 3

2b Leaf blades ± twisted, with margins downwardly deflected. H. foetidus, lividus & subsp. corsicus, niger, orientalis, purpurascens, viridis & subsp. bocconei: Macrosiphum hellebori

3a Leaf blade, more rarely petiole, with pustule-like necrotic oval swellings, up to 3 mm long, visible on both sides or on underside only; usually in two rows along the midrib. Each pustule containing a greenish-white egg; after emerging the larva lives freely on the leaf blade. “Procecidium” (oviposition scar, not a true gall). H. foetidus, niger, viridis: Monophadnus latus

3b Weak, at first ± vitreous, spindle-shaped swellings on stems and petioles. H. viridis: Physoderma deformans

4a Galls caused by rusts and smuts => 5

4b Galls caused by false mildew. Systemic infection of overwintering mycelium in rhizome. The diseased leaves are smaller, yellowish, the segments ± distinctly spoon-shaped downwardly deflected and curved; soon covered by a widespread, dense layer of conidia. H. dumetorum, foetidus, niger, odorus, purpurascens, viridis & subsp. istriacus: Peronospora pulveracea

5a Initially grey translucent smut bulges of variable size on all green parts, soon erupting and with black dusting. Helleborus spp.: Urocystis floccosa

5b Yellow aecia pads associated with spermogonia on gall-like swollen, sometimes ± bent petioles and leaf blades. Helleborus spp.: Puccinia actaeae-elymi

5c In similar aecia. Helleborus spp.: Puccinia actaeae-agropyri

1a On root collar, inner basal rosettes or on above-ground plant parts => 2

1b Spindle- or nodule-shaped swellings on roots, up to 5 mm long. Helichrysum spp.: Meloidogyne hapla

2a On upper stem parts, leaves or inflorescences => 4

2b Inside basal rosettes or on root collar => 3

3a Top of rosettes including an almost onion-shaped gall, up to 8 mm high and 5 mm wide. One larva inside. H. arenarium: Actinoptera discoidea

3b Globular or nodular, up to 1 mm long galls which are sometimes clustered and variously coalesced on root collar. The inside filled with initially bright-, later on chestnut brown spore masses. H. arenarium: Entyloma magnusii

4a On leaves and inflorescences => 6

4b On shoots => 5

5a Spindle-shaped swellings of the stems or inflorescence, up to 25 mm long. Later on the caterpillar bores downward in the pith over various length. H. arenarium: Unidentified lepidopteran

5b Spindle-shaped stem swellings about 6 mm long and 4 mm thick. Containing a single larva. H. arenarium: Actinoptera discoidea

5c Terminal leaves grouped in a subspherical mass of 10–15 mm in diameter, or terrminal bud swollen, ovoid or spindle-shaped (10 x 4.5 mm), covered with pubescent leaves. Large axial cavity containing a single larva. H. italicum, litoreum, pendulum, stoechas: Actinoptera mamulae

6a On inflorescences or capitula => 7

6b The middle part of single or several leaves variously bent downward and ± curled by froth-covered nymphs. H. bracteatum: Philaenus spumarius

7a Inflorescence stunted, bunched. Leaves ± rolled. Helichrysum spp.: Brachycaudus helichrysi

7b Capitula deformed; receptacle hardened. Containing a single larva. H. arenarium: Actinoptera discoidea

1a On leaves or stems => 2

1b On inflorescences or flowers => 5

2a Malformations lacking fructifying fungal sori on surface => 3

2b Leaf veins and -stalks with yellowish, spindle-shaped or elongated sometimes curved bulging swellings bearing aecia. E. campestre, creticum, falcatum, glomeratum, tricuspidatum: Puccinia eryngii

2c Leaves with fawn-coloured raised spots, 1–3 mm across, containing yellow-brown smut spores. E. planum: Entyloma eryngii-plani

3a Malformations on leaf blades => 4

3b Conspicuous swellings, up to 15 mm thick, usually expanded, multi-chambered, on stems and petioles. Inner wall of chamber covered with fungal hyphae. Each chamber containing a red larva. E. amethystinum, campestre, maritimum, tricuspidatum: Lasioptera eryngii

3c Malformation of stem. E. campestre, planum: Inducer unknown

4a Leaf blade reduced, rolled upwards, curled and discoloured. E. campestre, maritimum: Unidentified aphid

4b Leaf blade often with many distinct protruding or indistinct, rotund or angular pustules, 1–3 mm across, at first sometimes violet, soon browned, with many spores inside. E. alpinum, campestre, maritimum, planum: Entyloma eryngii

5a Style of flower thickened, ovary stunted. E. campestre: Unidentified gall midge

5b Centre of (partial) umbel swollen, globular or club-shaped; gall uni-, also multi-chambered, each containing a red larva. E. campestre: Lasioptera carophila

1a On parts above ground => 3

1b On roots or root collar => 2

2a Succulent, broad spindle-shaped or acuminate cylindrical, compact swellings on main- and major side roots. E. gallicum, nasturtiifolium: Plasmodiophora brassicae

2b Almost globular, 5‒10 mm long, one- also several-chambered swellings close to root collar. Containing a single white larva. E. gallicum: Ceutorhynchus assimilis

3a On leaves and stems => 4

3b Flowers swollen; unopened. Calyx enlarged, corolla and anthers necrotic. Stamens and stigma thickened. At maturity containing several white, non-jumping larvae. E. gallicum: Gephyraulus raphanistri

4a Malformations caused by animals => 5

4b Pads of at first closed, glossy, porcelain-like, with mealy dusting sori on various plant parts after rupturing. E. gallicum, nasturtiifolium: Albugo candida

5a Leaf blade with conspicuous, pale green swellings and deflected margins. E. gallicum, abyssinicum: Brevicoryne brassicae

5b Spindle-shaped often deep green swellings on petioles, midrib or stems, up to about 15 mm long. Containing a single larva. E. gallicum, abyssinicum: Ceutorhynchus chalybaeus

5c Leaves clustered on shoot tip or young inflorescences and transformed into a ± fleshy to spongy gall. E. incanum: Contarinia nasturtii

1a On parts above ground => 4

1b On roots or root collar => 2

2a On roots => 3

2b Almost globular, fleshy swellings on root collar, up to 7 (10) mm long, one-chambered. Containing a single larva. E. vesicaria: Ceutorhynchus assimilis

3a Small swellings, up to 5 mm long, nodular or ± spindle-shaped on side roots bearing some adventitious roots. E. vesicaria: Meloidogyne hapla

3b Conspicuous, fleshy swellings of variable size mainly in main- and major side roots. Many cells containing masses of minute spores inside. E. vesicaria: Plasmodiophora brassicae

4a On flowers or fruits => 8

4b On vegetative parts => 5

5a Malformations caused by animals => 6

5b Dense, at first closed glossy, porcelain-like bulging swellings on all green parts, with after rupturing mealy dusting of sori. E. vesicaria: Albugo candida

6a On stems or leaves => 7

6b Shoot tips, also axillary buds, stunted. Leaves as well as flower buds densely clustered; leaf base fleshy swollen, gall bodies variously enveloped by disfigured parts. Containing several white to pale yellow larvae. E. vesicaria: Contarinia nasturtii

7a Spindle-shaped, up to 15 (20) mm long, often deep green swelling on petioles, leaf veins or stems. Containing a single larva. E. vesicaria: Ceutorhynchus chalybaeus

7b Leaf blade deflected at margin; leaf blade variously strongly arched or folded, often pale green, sometimes reddish marbled. E. vesicaria: Brevicoryne brassicae

8a Flowers swollen, unopened. Containing several white to pale yellow larvae. E. vesicaria: Contarinia nasturtii

8b Similar flower galls; but contrary to the ± rotund-oval previously reported galls on Eruca usually ± conical and more conspicuous. Containing several non-jumping, also white when mature, larvae. E. vesicaria: Gephyraulus raphanistri

8c Large part of silique swollen, yellowish. Containing several white larvae. E. vesicaria: Dasineura napi

1a On parts above ground => 3

1b On roots or root collar => 2

2a Roots with conspicuous, mostly, spindle-shaped to cylindrical, fleshy swellings. Inside the galls are cells containing spore masses. D. erucoides: Plasmodiophora brassicae

2b Root collar with one to several rotund galls, up to 5 mm long, with a curved larva inside. D. muralis: Ceutorhynchus assimilis

3a On flowers and siliques => 7

3b On stems or leaves => 4

4a Localised or extensive deformations caused by animal gall causers => 5

4b Leaf blade on the underside with flat, rotund cushions. Leaf axial parts or stem with ± expanded, sometimes distorted bulge-like swellings, initially covered with closed dense white sori, at first-glossy, porcelain-like, with mealy dusting after opening. D. muralis, tenuifolia: Albugo candida

5a Deformations caused by aphids => 6

5b About 10–15 mm long, spindle-shaped, partially deep green swellings on the midribs or stems. Containing a single larva. D. muralis, tenuifolia: Ceutorhynchus chalybaeus

6a oung lateral shoots distinctly stunted; occupied by conspicuously reduced and deformed, more densely situated, leaves. D. tenuifolia: Lipaphis rossi

6b Leaf blades folded locally, leaf margins rolled. D. muralis, tenuifolia: Brevicoryne brassicae

7a Malformations caused by gall midges => 9

8b Other causers => 8

8a Greening of flowers. D. muralis, tenuifolia: Brevicoryne brassicae

8b Ovaries in one or several flowers of an inflorescence deformed, narrowed and elongated; anthers shrivelled, corolla stunted; ± greened; calyx partially conspicuously enlarged. On many parts bulge-like white fungal sori occur. D. erucoides, muralis, tenuifolia, virgata: Albugo candida

9a Malformations of flowers or flower parts => 10

9b Swelling of silique => 11

10a Single or several buds per inflorescence distinctly swollen, unopened. Similar galls; calyx and corolla sometimes less swollen. larva usually lighter yellow, jumping. D. muralis, tenuifolia: Contarinia nasturtii

10b Swollen flower buds. White, non-jumping larvae. D. muralis, D. catholica, D. erucoides: Gephyraulus diplotaxis

10c Swollen siliques, inside only one larva. Pupation in gall. Two generations. D. tenuifolia: Asphondylia stefanii

11a Spindle-shaped swelling of silique, often silique bent at right angle. D. tenuifolia: Dasineura napi

11b Siliques swollen, containing a single orange midge larva. D. tenuifolia:
Asphondylia stefanii

11b Siliques turgid, deformed and curved. D. tenuifolia: Dasineura napi

1a On parts above ground => 2

1b Roots with nodular swellings. B. sempervirens: Meloidogyne hapla

2a On buds, shoot tips or leaves => 3

2b Flowers greened; inner parts thickened, succulent; without abnormal pubescence. B. sempervirens: Eriophyes canestrinii

= Also Eriophyes buxi has been recorded, presumably as inquiline, from such galls

3a On leaves => 6

3b On buds or shoot tips => 4

4a Malformation of many terminal leaves => 5

4b Buds enlarged, transformed into a globular gall, up to 4 mm long, loosely grey pubescent. Leaves with small bladder-like swellings. B. sempervirens: Aceria unguiculata

5a Leaves on shoot tip clustered, tuft-like, almost hemispherical or arched, spoon-like, often sticky on inner side. Froth-covered nymphs flattened, greenish covered with whitish pubescence. B. balearica, sempervirens, microphylla: Psylla buxi

5b Young leaves deflected, black aphids on underside. B. sempervirens: Aphis fabae

6a Malformations induced by animals => 7

6b Up to about 2 mm wide, almost half-globular, compact, at first yellowish-green, later on dark brown telia; containing 2-celled teliospores. Often several sori on the underside of locally hypertrophied leaves. B. microphylla, sempervirens: Puccinia buxi

6c The infested leaf parts eventually dry and fall out; after that it looks as if the plant has been grazed by an insect. B. sempervirens: Mycosphaerella buxicola

7a Leaf blade usually with yellowish-green, vaguely defined, ± rotund-oval blisters, often close to midrib on upper side, on underside later on ± translucent, flat bulging. Often several per leaf, ± coalescing. Each contains one or more larvae, at first white, later on orange-yellow. B. balearica, microphylla, sempervirens, wallichiana: Monarthropalpus flavus

8b Leaf blades with small pustules. Parenchyma loosened from lower epidermis. Cavity contains many gall mites. B. sempervirens: Eriophyes hypophyllus

1a Malformations of above-ground parts => 2

1b Root with node-shaped tumefaction. A. lappa: Ceratapion onopordi

1c Gall in root or root collar; spindle-shaped, about 5–10 mm, containing a larva or pupa. A. minus: Cleonis pigra

= Caterpillars of the tortricid Epiblema scutulana, with yellowish brown head, bore into the stem and underground parts. They hibernate in the upper section of their gall cavity. The plant may show a local swelling or shortening of the internodes

2a On leaves => 3

2b Capitula malformed. Larvae in the swollen receptacle. A. lappa, minus, tomentosum: Tephritis bardanae

= Gall-like inflation of the ovary is caused by the tephritid fly Chaetostomella cylindrica

2c Mature achene slightly swollen, with tiny larval entrance hole in upper third and larger hole at base blocked with debris; contains a larva. A. lappa, minus, tomentosum: Terellia tussilaginis

2d Woody galls in capitula. Arctium sp.: Urophora solstitialis

= Hardening and gall-like malformation of the capitula on burdocks might be attributed to the larva of the gelechiid moth Metzneria lappella

3a Leaf blades over extensive areas curled, rolled => 6

3b Leaves with galls => 4

4a Malformations caused by fruiting bodies of fungi situated on the surface => 5

4b Leaves of young plants, close to the ground, on the underside or on the petioles with many ± hemispherical, golden yellow warts, less than 1 mm long. A. lappa, minus: Synchytrium aureum

5a Aecia bearing, ± distinctly upraised yellow bulges on the underside of the leaves; usually on the leaf blades, rotund, up to 10 mm long; less frequently on the main veins, but more conspicuous there, long oval to spindle-shaped. A. lappa, nemorosum: Puccinia silvatica

5b Yellowish, ± oval, 2–5 mm long, weak bulges and curves on the leaf upperside on the main veins. Bulges only on the upperside, soon occupied by cinnamon dusty uredinia. A. lappa, minus, tomentosum: Puccinia calcitrapae

6a Margins of younger leaves rolled inwards, curved and ± curled; older leaves with dark green, slightly bulging spots. Black aphids on the underside. Arctium spp.: Aphis fabae

6b Larger leaf blades with extensive loose downward rolls, mostly obliquely over the top; smaller ± trowel-shaped converging; below close to the froth-covered nymph crooked and tubercular; dark green. Arctium spp.: Philaenus spumarius

1a On above-ground parts => 2

1b Roots with spindle-shaped, crooked or half screw-shaped bent swellings a few mm long. A. odoratum: Subanguina radicicola

2a On inflorescences or flowers => 6

2b On vegetative parts => 3

2c Whitish, at surface yellowish or brownish patches, which envelope a large area of the upper part of stem, of which further development is stunted. Node of stem rarely swollen, encircled by fungus stroma, yellowish when mature; several nodes may be affected; flowering stunted; stroma contains narrow asci and filamentous spores. A. odoratum: Epichloë typhina

2d At the base of stem, weak swelling containing one (or maybe sometimes several) white larva or flax seed like puparium. A. odoratum: Mayetiola sp.

3a Leaves with several parallel stripes caused by smuts => 5

3b Complete plant stunted in development => 4

4a Shoot at base slender onion-like swollen; plant more densely foliate. Stem not or only slightly developed. Leaves ± undulate and thickened; many eelworms inside. A. odoratum: Ditylenchus dipsaci

4b Complete plant stunted; inflorescence discoloured; contains a fly maggot. A. odoratum: Unidentified dipteran

5a Spores solitary, 8–12 µm across. Mass black. Stripes also occurring on stems and parts of spikes which remain closed for a longer time. A. odoratum: Ustilago striiformis

5b Spores in clusters of 2–5, enveloped by sterile auxiliary cells. Smut stripes occasionally also on leaf sheaths, stems and affected spikes. A. odoratum: Urocystis roivainenii

6a Inflorescence disfigured by animal parasites => 7

6b Ovary transformed into inconspicuous smut grains about 2 mm long, 1 mm wide. A. odoratum: Tilletia anthoxanthi

7a Axis of inflorescence wriggled; spikelets conglomerate. A. odoratum:
Unidentified tarsonemid mite

7b Inflorescence and flowers disfigured. Reproductive organs aborted. Glumes twisted or irregularly folded; in case of weaker infestation often dark red or violet, bleached if strongly infected. A. odoratum: Aceria tenuis

1a On needles, on young, ± stunted shoots or on developing buds => 4

1b On lignified younger or older stem parts => 2

1c arvae develop gregariously (1−8 together) inside young seeds in cones. A. alba, cephalonica, nordmaniana: Resseliella piceae

= Fresh resin masses of damaged shoots of A. alba rarely may contain gall midge larvae of Resseliella crassa and/or R. resinophaga

2a Older lateral shoots, sometimes also the stems, occupied by conspicuous witches’ brooms or mistletoes => 3

2b Axial parts of younger shoots often severely stunted, with ± club-like to nodule-shaped, also forked and twisted swellings, or older stem parts with irregularly expanded, ± bulging proliferations of bark. Sometimes also the buds are transformed into globular or egg-shaped galls. Abies spp.: Dreyfusia piceae

2c A very similar aphid may occur on young plants of A. alba, nordmanniana: Dreyfusia merkeri

3a Witches’ brooms with erect main shoots, abundantly branched, developing from globular to barrel-shaped, often conspicuous thickenings. Needles distinctly shortened, thickened, yellow-green, directed to all sides, falling in autumn. A. alba and several foreign species. Melampsorella caryophyllacearum

= In Melampsorella galls and other cancer-like malformations on conifers the tortricid moth Cydia duplicana, as well as the gelechiid Chionodes electella occasionally develop

3b From bulges, club- and barrel-like swellings of branches or stems arise
Viscum album subsp. abietis

4a On young shoots or on needles => 5

4b Developing buds severely stunted, globular swollen and disfigured, hard and browned. Mites inhabit strobili, apparently causing deformation and atrophy. A. alba, concolor, pectinata: Trisetacus floricolus

5a On many curved needles of ± shortened side shoots => 6

5b Lower third of needles predominantly with brown or red swelling, up to 2 (3) mm long, especially rotund-oval to compact spindle-shaped at base and laterally protruding, expanded over only one or over both needles. Larvae orange-yellow, jumping. A. alba and foreign species: Paradiplosis abietispectinatae

6a Top of shoot slightly shortened. Needles of young shoots weakly swollen, ± tuft-like upwardly converging, exposing wax stripes on the underside; many white woolly aphids between the needles during April-June. Abies spp.: Mindarus abietinus

= Between the needles are pale green aphids of Mindarus obliquus occur in white fluffy wax, resembling those of M. abietinus. Contrary to that species, no malformation of the needles occurs.

6b Needles on the stunted tips of young shoots, predominantly of smaller plants, accumulated, bottle brush-like, partially downwardly deflected. A. alba, nordmanniana etc.: Dreyfusia nordmannianae and/or D. merkeri

6c Another inhabitant on bark of Nordmann fir, also alternating with Picea orientalis: Dreyfusia prelli

1a On above-ground parts => 2

1b Roots with nodular or slender spindle-shaped swellings. Meloidogyne chitwoodi

2a Malformations caused by weakly dusting fungi => 7

2b Malformations caused by animals => 3

3a Malformations mainly on young plants caused by animals developing inside => 6

3b More or less distinct leaf rolls caused by aphids => 4

4a Greenish aphids => 5

4b Aphids glossy dark-brown. Young leaf blades, if weakly infected, slightly rolled and discoloured mainly at base, soon withering. Sipha maydis

5a Adult wingless aphids oblong-oval, 1.75–2.6 mm long, powdered, dark green to bluish black, with very dark, brown-black extremities. Rhopalosiphum maidis

5b Wingless aphids rotund-oval, 1.6–2.4 mm, not powdered, dull olive-green to dark grey-green, with green translucent to brown, at the tip dark-brown extremities. Rhopalosiphum padi

6a Plant excessively leafy. Leaves contorted and disfigured, partially twisted. Shoots stunted, at base spongy, swollen; internodes distinctly shortened and thickened. Ditylenchus dipsaci

6b Shoots of young plants stunted; slightly swollen just above ground; plants additionally leafy; inner leaf destroyed. Leaf sheaths and -blades ± twisted. Usually several yellowish-white maggots at base of shoots, up to 4 mm long, which feed on various plant parts Oscinella frit

6c In addition to frit fly occurring on maize and with similar biology is the closely related: Oscinella pusilla

7a Different plant organs with pea- to even child head size, at first white-grey covered, bulging swellings, which release the previously smeary, then dusty, blackish single smut spores when ripped open. Mycosarcoma maydis

7b The female and also the looser male inflorescences completely or only partially transformed into a unified smut mass, initially enveloped by a whitish to reddish membrane. Diseased flowers sometimes with leaf-like structures. Spores united in balls. Sphacelotheca reiliana

7c Inconspicuous and ephemeric fungal down on the underside of yellowing leaves of seedlings. It consists of erect conidiophores that apically are dichotomously branching several times, each terminal branch ending in a conidium. Peronosclerospora maydis

1a On leaves, stems or/and inflorescences => 2

= As causer of root galls on V. locusta has been recorded the Root knot eelworm Meloidogyne hapla

1b Ovary swollen, up to 7 mm long, disfigured. Containing a single white larva. V. carinata, dentata, locusta, rimosa: Cecconia valerianellae

2a Malformations on vegetative organs, sometimes encroaching onto inflorescence primordia => 3

2b Many flowers in an inflorescence conspicuously disfigured. Corolla greatly enlarged, transformed into a lobed, succulent annular disc. Stamens corolla-like. Valerianella sp.: Unidentified gall mite

3a Malformations caused by fungi fruiting on outside => 5

3b Malformations caused by animals => 4

4a Young plants severely stunted. Leaves from basal part upwards variously spongy swollen, the higher situated parts ± disfigured. Stem primordia similarly thickened. V. dentata, locusta: Ditylenchus dipsaci

4b Leaves widened and shortened, ± distorted or rolled. Inflorescence axis shortened. Flowers clustered into rotund, pale green balls. Calyx enlarged, often deeply incised. Tips almost leaf-like, greened or leafy. Stamens aborted. Bracts folded and distorted. V. carinata, coronata, dentata, locusta, rimosa: Trioza centranthi

5a Fungi in expanded, not distinctly restricted malformations => 6

5b Plants usually infected systemically and often not reaching the flowering stage. Organs variously disfigured. Sori on leaf underside, or on all sides of axial parts with ± uniformly arranged whitish aecia. V. carinata, dentata, locusta, rimosa: Puccinia gladioli

6a Plants largely or completely covered by a loose, dusty mycelium. Infected parts variously ± disfigured or often not gall-like V. carinata, dentata, eriocarpa, locusta, rimosa: Golovinomyces orontii

6b On various Erysiphaceae [powdery mildews] develops the widely distributed and rather frequent Ampelomyces quisqualis

6c Systemically infected shoots pale green, on axial parts weakly hypertrophied; leaves slightly thickened, leaf blades ± stunted, margins slightly deflected, with a down of dirty white, branched conidiophores on underside. V. carinata, dentata, discoidea, locusta, rimosa: Peronospora valerianellae

6d Leaves and stem, usually with many, minute greenish to brown globular warts. V. locusta: Synchytrium valerianellae

1a On above-ground parts => 2

1b Roots sometimes with minor swellings, from which cysts erupt up to 1 mm long, lemon-yellow later on. Trisetum sp.: Heterodera avenae

2a On vegetative organs => 4

2b Galls on ovaries => 3

3a Ovary transformed into an oblong gall protruding far outside the spike. T. flavescens: Anguina agrostis

3b Ovaries within the unopened, not disfigured, glumes strongly elongated, abnormally thin, sometimes conspicuously curved. Each floret containing a pale brick- to orange-red larva. T. flavescens: Dasineura triseti

4a Malformations caused by animals on culms or leaves => 6

4b Leaf blades, rarely sheaths, culms and parts of spikes with several long parallel stripes of smut => 5

5a The long stripes of smut contain a black spore powder. Spores 2–8 in balls, completely enveloped by many sterile auxiliary cells. T. alpestre, flavescens, spicatum: Urocystis triseti

5b The smut mass consists of 8–12 μm single spores. Trisetaria panicea, Trisetum spicatum: Ustilago striiformis

6a On culms => 7

6b Leaf blades ± thickened, longitudinally upwardly rolled inwards and curved, screw-like. T. flavescens: Unidentified tarsonemid mite

7a Culm slightly swollen at base of the ± stunted inflorescence. T. flavescens: Oscinella frit

7b Culm, with weak, slightly rimmed depressions underneath the sometimes slightly arched leaf sheaths, usually close to a node; each containing an orange-yellow larva. T. flavescens: Lasioptera calamagrostidis

1a Malformations on leaves, sometimes extending onto the stems => 2

1b Shoot axis or petiole ± buckled or swollen spindle-shaped, sometimes conspicuously curved; often with several flat, oval, rimmed depressions, containing inducer. S. minor: Planchonia arabidis

2a Malformations without conspicuous pubescence => 3

2b Above-ground parts variously disfigured, on most expanded areas with abnormal, dense, whitish, hair felts. Hairs long, twisted. S. minor & subsp. balearica, officinalis, verrucosa: Aceria sanguisorbae

3a Leaf fold, roll or curl caused by animals => 6

3b Small, wart-like or expanded bulging galls caused by fungi => 4

4a Galls bulging, several mm long. Spores develop on gall surface => 5

4b Galls wart-shaped, many-celled, less than 1 mm across, yellow; with many on leaf underside, on leaf midrib, -stalk or young stems; sometimes coalescing into crusts or ridges and causing bends. S. minor, officinalis: Synchytrium aureum

5a Leaf veins, -midrib or stalk, sometimes also young stems, with slightly bulging, sometimes distinctly bent swellings of different length; leaf blades with rotund red-brown pads on upperside, mainly protruding on underside. Galls often brick-red, soon covered with orange spores. Teliospores (2) 4 (5)-celled. S. minor & subsp. balearica, officinalis, rupicola, verrucosa: Phragmidium sanguisorbae

5b Expanded, often ± curved bulges on leaf veins, -spindles, -stalks, also on stems; leaf blade with rotund pads, mainly on underside. Gall soon covered with brick-red spores; telia develop on both sides in arched carbon-black pads, sometimes coalescing with caeoma-sori. Teliospores 4‒22-celled. S. officinalis, verrucosa: Xenodochus carbonarius

5c Malformation of leaf. S. alpina, canadensis, minor & subsp. balearica, officinalis, verrucosa: Podosphaera ferruginea

5c Leaves curled and reddened. S. minor, officinalis: Peronospora sanguisorbae

6a Leaflets curled and ± rolled downwards => 7

6b Halves of leaflet folded upwards, pod-like; especially slightly thickened at veins; outside often ± grey-green, inside ± reddened. Often all leaflets of a leaf are galled. Larvae very many, orange-red. S. officinalis, much rarer on S. minor, officinalis: Dasineura sanguisorbae

7a Malformations caused by spittlebugs or sawfly larvae => 8

7b Leaf blades contracted, curled. S. minor: Unidentified aphid

8a Midrib and leaflet stalks of the still young often pale green leaves slightly thickened and ± stunted, bunched together; axis curled variously up to almost spirally. Leaf blades of leaflet ± folded upwards, often deflected in apical part. S. minor, officinalis: Claremontia puncticeps

8b Especially apical part of leaf midrib distinctly shortened and curved downwards. Leaflets ± bunched together, crumpled, partially dark-green. Froth-covered nymph on underside. S. minor, officinalis: Philaenus spumarius

1a On parts above ground => 4

1b On roots or subterranean stem parts => 2

1c White, velvet cover on all parts of the plant, even underground. Attacked parts turn brown and wither. The conidia (in fact, sporangia) are ovoid or lemon-shaped, with an indistinct apical papilla. They are formed at the tip of seemingly undifferentiated hyphae, that here and there show irregular swellings. Phytophthora infestans

2a Nodular or slender spindle-shaped galls, on roots located distant from surface => 3

2b Buds or adventitious buds of subterranean stem parts, also roots, developing into smaller proliferations, exceptionally up to 20 mm long. Synchytrium endobioticum

3a Nodular swellings, often many and ± coalescing. Meloidogyne hapla etc.

3b Roots usually with shorter or longer, sometimes interrupted, slender, 2–3 mm broad swellings and sometimes excessive development of side roots; this ‘root beard’ is usually situated above the galls. Globodera rostochiensis

3c Tips, often of many roots, slightly swollen over various lengths. Plant often conspicuously stunted. Also many eelworms inside and outside the tissue: Pratylenchus pratensis

3d Root with rounded galls, usually several together like a string of beads; on tomato in glasshouses. Nacobbus cf. aberrans

= Nacobbus serendipiticus (tomato eelworm) is causing spindle-shaped galls on roots in glasshouses

4a On leaves and flowers => 6

4b On stems, sometimes encroaching on leaf midrib => 5

5a Up to 20 (30) mm long, rotund bulge, mainly on root collar, secondarily also on higher stem parts. Agrobacterium tumefaciens

= In cases of the moderately frequent “tomato cancer”, better known as “bacterial tomato withering/drooping” the causer is Corynebacterium michiganense

5b Pale green, spongy, ± expanded swelling, often associated with distortion of ± stunted parts. Ditylenchus dipsaci

6a Various curls or rolls, often of several terminal leaves, caused by aphids => 7

6b Malformations of flowers often with bladder-like swelling, extensively conjoined calyx leaves as well as largely stunting of partially greened corolla leaves and stamens and sometimes enlarged and disfigured ovaries on plants with reduced, often bulging leaves. Stolburg disease

6c Individual flower or part or all of inflorescence greened and leafy (phyllanthy), very haired, containing mites. Aceria lycopersici

7a Aphid dull-black, about 2.5 mm long. L. esculentum: Aphis fabae

7b Aphids pale yellowish to green, 1.8–2.9 mm long, siphunculi pale at base, darker, with a dark spot at tip. Aulacorthum solani

7c Aphid green, often with a dark, green longitudinal stripe on back. Body spindle-shaped oval, glossy in adults, dusted with greyish wax in froth-covered nymphs. 1.7–3.6 mm. Siphunculi brownish, ¼–⅓ of body length, twice as long as cauda. Alates with pale brownish-yellow thorax, otherwise lacking pigmentation on back. Macrosiphum euphorbiae

1a On parts above ground => 3

1b On roots or root collar => 2

2a Irregular cylindrical, usually swelling on all sides, of variable length, on side roots and younger parts of main root. L. annua, rediviva: Plasmodiophora brassicae

2b Globular galls on root collar, with central larval chamber. L. annua, rediviva: Ceutorhynchus assimilis

3a On flowers or fruits => 9

3b On vegetative parts => 4

4a Malformations caused by animals => 6

4b Malformations caused by fungi => 5

5a Sori at first closed, glossy, porcelain-like, the conidia later develop on basal conidiophores in rows on rupturing, dusty pads. L. annua, rediviva: Albugo candida

5b Sori dull, conidia on branched conidiophores. L. annua, rediviva: Hyaloperonospora lunariae

6a Malformations caused by external plant feeders, aphids or spittlebugs => 8

6b Causers inside malformations; larvae of weevils => 7

7a Up to about 15 mm long, rotund to flattened spindle-shaped galls, also deep green inside with central larval chamber, on midrib, also petioles; occasionally on younger stem parts. Containing a single larva. L. annua: Ceutorhynchus chalybaeus

7b The shorter petioles of higher leaves as well as the lower part of the midrib are ± conspicuously deflected; inside are translucent, dark feeding tunnels, with wall cells often regenerating, causing swelling of the organs and sometimes even rupture. Containing a single beetle larva. L. annua: Ceutorhynchus pallidactylus

8a Leaf blades rolled- or deflected, almost nest-like. On main venation close to the froth-covered nymph curled and darker green than the parts towards leaf blade margin. L. annua, rediviva: Philaenus spumarius

8b Malformation of several, incompletely unfolded leaves on shoot tips, caused by mealy powdered grey-green aphids. L. annua, rediviva: Brevicoryne brassicae

9a Flowers thickened, unopened. L. annua: Contarinia nasturtii

9b Siliques severely disfigured, slightly discoloured, warty and bulging; seeds aborted. L. annua: Brevicoryne brassicae

1a Galls on stems, leaves, flowers or fruits => 2

1b Swellings on roots, up to several cm long, 5–10 mm wide. Hesperis spp.: Plasmodiophora brassicae

2a On flowers or fruits => 6

2b On stems or leaves => 3

2c Malformation of all organs caused by mildew. H. matronalis: Albugo candida

3a On leaves => 4

3b Shoot axis on root collar with rotund, one-chambered fleshy swellings, sometimes with several coalesced, hence multi-chambered, bulging. H. matronalis: Ceutorhynchus assimilis

3c Cancer-like galls. H. matronalis: Agrobacterium tumefaciens

4a Rolled margins or curling of leaf blade => 5

4b Petiole or midrib with spindle-shaped swelling, up to 15 mm long, often deep green. H. matronalis, nivea: Ceutorhynchus chalybaeus

4c Leaf underside with a greyish down of erect conidiophores that distally are several times branched. At each tip an egg-shaped conidium. H. matronalis: Hyaloperonospora hesperidis

5a Leaf margin at leaf blade base, often up to the middle of the leaf blade or farther with 2 mm wide, compact roll. H. matronalis: Inducer unknown

5b Loose roll of leaf margin or upward fold of leaf blade. H. matronalis: Brevicoryne brassicae

6a Flower buds swollen, unopened. H. laciniata, nivea: Cause unknown – ? gall midge

6b Fruit locally disfigured, sometimes bent and swollen. H. matronalis: Inducer unknown

1a On above-ground parts => 2

1b Roots with 2–3 mm long, spindle-shaped swellings, on which occasionally some lateral roots have developed. G. uliginosum: Meloidogyne hapla

2a Whole plant, or major parts, deformed by aphids or cercopids => 8

2b Galls on shoots => 3

3a Spindle-shaped or globular galls of almost constant shape, but of various size => 5

3b Malformations of various shape and nature => 4

4a Galls on young, often severely stunted, plants. Basal parts, especially stems, also including the leaf bases, spongy, swollen, with many eelworms inside. G. uliginosum: Ditylenchus dipsaci

4b Sometimes strong swelling of the stem on the tip of ± developed shoots or the inflorescence. Leaves clustered, with swollen base, abnormally pubescent. G. sylvaticum: Cause unknown – ? gall mite

5a Galls spindle-shaped, with larvae inside => 6

5b Rotund, up to 5 (10) mm long galls; the inside containing whitish-yellow, later on rust brown, spore masses; predominantly on root collar, occasionally concentrated in groups. More rarely small galls on higher stem parts, even in the inflorescence. Laphangium luteo-album, G. sylvaticum, G. uliginosum: Entyloma magnusii

6a Inside the galls are larvae with head capsules => 7

6b Spindle-shaped swellings, up to 6 mm long and 4 (5) mm thick, usually in upper stem parts, the inside with a sometimes laterally situated whitish larva without distinct head capsule. G. sylvaticum, uliginosum: Actinoptera discoidea

7a Hard ovoid, one-chambered swelling in flower head or stalk. One larva. G. sylvaticum: Acentrotypus brunnipes

7b Spindle-shaped swelling on terminal part of shoot. With a yellowish-white, transversely lightly pink striate caterpillar with pale to dark brown head inside. Laphangium luteo-album: Eucosma albidulana

8a Caused by aphids => 9

8b Shoot stem usually stunted on one side, leaves clustered, the leaf blades curved downward, ± curled and dark green close to the froth-covered nymph. G. sylvaticum: Philaenus spumarius

9 Central part of rosettes deformed; or top of vegetative shoots, also the inflorescence, with shortened and sometimes twisted stem; leaves, sometimes capitula, clustered, rolled, curved. Aphids white frosted by copious secretion of wax. Filago arvensis, germanica, lutescens; Gnaphalium sylvaticum, uliginosum: Pemphigus populinigrae

9b Top of shoot stem stunted, leaves clustered, curved. Aphid bright yellow to yellowish-green, 1.5–2 mm long, without secretion of wax. G. sylvaticum, G. uliginosum: Brachycaudus helichrysi

1a Galls on higher situated organs or on rosette leaves => 2

1b Rotund swellings, 2–3 mm long on root collar or stem base. G. campestris, etc.: cf. Smicronyx reichi

2a On higher situated parts or on single organs => 3

2b Leaves clustered, rosette-like. Gentianella amarella: Unidentified gall mite

3a On flowers => 7

3b On vegetative organs => 4

4a On shoot tips, axial parts of shoot or leaves => 5

4b Rotund ± one-sided ± bulging galls, up to 4 mm long, on axial parts of shoots, usually close to a node. On ± severely stunted stems symmetrical barrel- to spindle-shaped galls, up to about 8 (10) mm long. With a large chamber inside which may continue into the pith. Gentianopsis ciliata, Gentianella germanica: Smicronyx reichii

4c Stem, usually in lower half, with broad spindle-shaped one-sided flattened and often strongly deflected swelling, 6–10 mm long, containing the causer in the sharp bend below an arched scale. Gentianopsis ciliata, germanica: Planchonia arabidis

5a Malformations by other causers than aphids => 6

5b Malformations of shoots associated with atrophied flowers and discoloured leaves. Gentiana asclepiadea, cruciata: Aphis gentianae

6a Axial parts stunted and distorted on one side. Inserted leaves deflected and variously curled. Gentiana/ Gentianella spp.: Philaenus spumarius

6b Rarely developing aecia in spring on sometimes slightly bulging, oblong-oval areas on stems, flower peduncles, less so on petioles and leaf veins. Gentiana/ Gentianella spp.: Puccinia gentianae

7a Malformations caused by gall mites => 8

7b Flowers slightly disfigured, unopened. Gentiana pneumonanthe; Gentianella amarella, campestris, germanica: Dasineura gentianae

7c Capsule rarely swollen; containing a weevil larva or pupa. Gentianella amarella, campestris, germanica: Smicronyx reichii

8a Inflorescence transformed into a rosette of small leaves; flowers variously ± greened or leafy, occasionally filled with ± disfigured organs or developing further. Gentiana/ Gentianella spp.: Aculus kerneri and/or Eriophyes gentianae

8b Malformations on flowers with conspicuous wrinkling of calyx and corolla. Gentiana bavarica: Unidentified gall mite

1a On parts above ground => 3

1b On roots or on root collar => 2

2a Roots with small nodular or spindle-shaped swellings. E. cicutarium:
Meloidogyne hapla

2b Adventitious buds on root collar circularly developing into ± cauliflower-like galls, up to 20 mm broad, not excessively pubescent. E. cicutarium: Aceria schlechtendali

3a On vegetative organs => 4

3b Flowers swollen, unopened; ovary sometimes slightly disfigured. Containing several orange coloured larvae. E. sanguineum, cicutarium: Dasineura geranii

3c Flower bud disfigured and swollen, perianth hypertrophied, stamens normally developed, staminodes and ovary atrophied. E. chium, ciconium: Aceria erodii

3d Flower swollen, corolla disfigured. E. chium, cicutarium, ciconium, malacoides: Limobius borealis

4a Localised wart- or bulge-shaped galls on vegetative organs => 7

4b Expanded malformations on leaves or several other organs => 5

5a Malformations on basal organs => 6

5b Leaf margins deflected, leaf blades of several leaves curled and bent. E. ciconium, cicutarium, malacoides, moschatum, trichomanifolium: Acyrthosiphon malvae

6a Plant ± stunted. Terminal organs clustered on often distinctly shortened internodes. Leaves almost sessile, lacerate, rolled downwards and bent; flower primordia stunted or variously leafy; inhabited parts often excessively pubescent. E. cicutarium: Aceria schlechtendali

6b Petioles, also lower parts of leaf blade of ± stunted plants, variously swollen, spongy and disfigured. Galls ± wrinkled, also on basal part of stem. E. cicutarium: Ditylenchus dipsaci

7a Indistinctly swollen, ± yellowish, often reddish to crimson margined sori bearing aecia on leaf midrib and leaf blades. E. cicutarium: Puccinia polygoni-amphibii

7b Aecia may occur on leaf midrib in conspicuously swollen bulges. E. cicutarium: Aecidium erodii-cicutarii

7c Less than a mm wide, purplish red, semiglobular warts, mainly on the lower leaves, often in large numbers. E. cicutarium: Synchytrium papillatum

1a On inflorescences or fruits => 5

1b On (terminal) shoots or leaves => 2

2a Galls on stems and shoot tip or distortion of complete shoots => 4

2b Leaves rolled at margin => 3

3a Leaf blade at margin narrowly rolled in; upper side with rotund flat grooves. B. rotundifolium: Unidentified psyllid

3b One or both halves of leaf blade loosely rolled upwards, slightly thickened and brittle; ± discoloured pale-green or violet; the roll contains flat, brown, mainly solitary froth-covered nymphs, white fringed at margins. B. falcatum: Eryngiophaga hungarica and/or Eryngiophaga lautereri

3c Youngest leaves at shoot tip or side shoots rolled in over one another, weakly cartilaginously thickened, pale-green or violet. Gall spindle-shaped, 10–25 mm long, often with its base geniculate, also complete malformation laterally bent outwards. Larvae yellow to orange-red. B. falcatum: Dasineura bupleuri

4a Basal part of stem with broad spindle-shaped, one-sided flattened, curved swelling, contains a froth-covered nymph under an arched scale. B. falcatum: Planchonia arabidis

4b Usually all shoots of plant diseased and pale-green. Shoots already running ahead in early spring, etiolated, often remaining sterile; leaf blades narrowed, at first with many spermogonia on underside, then with abundant aecia. Sori sometimes also occurring on slightly distorted stalks and stems. Bupleurum spp.: Puccinia bupleuri

4c In similar malformations on B. stellatum: Puccinia bupleuri-stellati

5a On bladder-like inflated fruits => 6

5b Centre of (partial) umbel ± swollen, club-shaped; gall sporadically also ± one-sided on stalk of umbel. Contains a red larva. B. falcatum, fruticescens, rigidum, rotundifolium: Lasioptera carophila

6a Inside an orange-red larva. B. falcatum, longifolium, praealtum, ranunculoides: Kiefferia pericarpiicola

6b Several red-yellow, jumping larvae. B. falcatum, longifolium: Parallelodiplosis bupleuri

1a On flowers or fruits => 6

1b On vegetative organs => 2

2a Malformations expanded over ± substantial areas of the shoot => 3

2b On smaller leaves, petioles or sometimes locally bent stems, spots pad-like arched on underside, bearing ± elongated bulges with terminally papilla-like narrowed telia with 2-celled teliospores which fall apart easily and then seemingly 1-celled. Sori on underside of larger leaf blades usually in circular arrangement in discoloured not thickened spots. Sori soon becoming powdery white because of direct germination of the teliospores. A. montana, retusa, serpyllifolia, tenuifolia: Puccinia arenariae

2c Sori usually more expanded. Fungus distinguished by black, terminally rounded, 2-celled telia. A. serpyllifolia: Puccinia hysteriiformis

3a Diseased parts etiolated, with sori of fruiting bodies of fungi => 5

3b Galls caused by animals => 4

4a Stem ± stunted, spongy, swollen; galls at surface ± rugose, pale green. A. serpyllifolia: Ditylenchus dipsaci

4b Leaves rolled downwards at tip of weakly stunted shoots. A. serpyllifolia: Myzus certus

5a Plants usually completely diseased. Shoots developing earlier and rigidly erect leaves pale green, narrowed, with yellow sori on underside. A. serpyllifolia: Melampsorella caryophyllacearum

5b Early infected buds or shoots develop further rigidly erect. Leaves pale green, small, partially spoon-like, arched downwards, with a down of branched conidiophores on underside. A. ciliata, foliosa, serpyllifolia: Peronospora campestris

6a Malformations of fruits => 7

6b Flower buds outwardly hardly changed. Anthers temporarily swollen, soon filled with black-violet spore masses, with dusting later on. A. ciliata: Microbotryum violaceum

6c Flowers ± swollen globularly, unopened. Inner organs soon destroyed and replaced by spore balls consisting of a yellowish-brown powdery dust. A. tenuifolia: Thecaphora saponariae

7a Capsule enlarged on thickened fruit peduncle, oval; contains a beetle larva. A. serpyllifolia: Unidentified snout beetle

7b Capsule outwardly hardly changed. Seed rudiments, also placenta, temporarily swollen, soon filled with red-brown spore masses. A. ciliata, graminea, obtusiflora incl. subsp. ciliaris, serpyllifolia: Microbotryum duriaeanum

1a On parts above ground => 2

1b Main- and side roots with conspicuous, spindle- to barrel- shaped succulent swellings. Inside with many cell masses with minute spores. A. arenosa, lyrata subsp. petraea, suecica, thaliana: Plasmodiophora brassicae

2a Malformations caused by fungi, with fructifications developing at surface => 6

2b Malformations caused by animals => 3

3a Malformations of flowers or siliques => 8

3b Spindle-shaped or expanded swellings on stems or petioles => 4

3c Large parts or complete plant disfigured. Shoot severely stunted; flower parts severely disfigured, often greened or reddened. Aphid more frequent on Arabis: A. lyrata subsp. petraea, thaliana: Lipaphis rossi

3d Leaf blade stunted, rolled upwards, curved; covered with abnormal pubescence. A. arenosa: Aceria drabae

4a Swellings ± spindle-shaped and glabrous => 5

4b Shoot severely stunted, like the basal parts of lower leaves variously swollen, spongy, pale green. A. thaliana: Ditylenchus dipsaci

5a tem with about 5–7 mm long, 2 mm thick, spindle-shaped swelling. The pith contains a single larva. A. arenosa, suecica, thaliana: Ceutorhynchus atomus and/or C. griseus

5b Rotund, fleshy swelling of the root collar, up to 10 mm; the single gall chamber containing a single legless, curved larva. A. arenosa: Ceutorhynchus assimilis

5c Spindle-shaped gall, 10‒20 mm long, in the leaf stalk (less often in the stem or a thick vein). A. arenosa: Ceutorhynchus chalybaeus

5d Shoot axis or petiole with spindle-shaped, often strongly arched thickening. Side branches of inflorescence ± shortened. A. thaliana: Inducer unidentified – ? lepidopteran

6a Malformations caused by fungi with white fruiting bodies => 7

6b Diseased shoots ± etiolated; internodes ± elongated and narrowed. Leaves often smaller, pale green; leaf blades slightly thickened, on underside over large areas with dense, ± rust brown sori. A. arenosa, halleri, petraea, thaliana: Puccinia thlaspeos

7a Sori densely clustered, bulging, at first closed, glossy, porcelain-like, then rupturing and with mealy dusting; oblong-oval on stems and inflorescence stalks, often arching the stems. On leaf underside rotund, often without malformations. Conidia developing in chains. A. arenosa, halleri, suecica, thaliana: Albugo candida

7b Sori expanded, with loose cover of branched conidiophores. Infected stems pale green, slightly thickened and arched, especially in flowering part; flowers severely stunted. A. thaliana: Hyaloperonospora arabidopsidis

7c Leaves somewhat disfigured with pale spots on the upperside, that correspond with a fungal bloom on the underside, consisting of erect, apically strongly branched conidiophores. A. arenosa, ? halleri, ? petraea: Hyaloperonospora cardaminopsidis

8a Flowers swollen, unopened; containing several pale yellow, jumping larvae. A. arenosa, cebennensis: Contarinia nasturtii

8b Flowers disfigured, ± leafy; abnormally pubescent. A. arenosa: Aceria drabae

8c Siliques slightly disfigured, hardly inflated. Young seed soon filled with yellowish to grey-violet masses of spores. A. petraea: Thecaphora thlaspeos

1a On above-ground parts => 2

1b Roots with small spindle-shaped or nodular swellings, up to 6 mm long. Allium spp.: Meloidogyne hapla

2a Locally restricted to expanded, bulging or non- protruding galls => 3

2b Complete plant stunted and disfigured. Leaves as well as sheaths and stems stunted, spongy thickened, curved and sometimes twisted, ± pale green, with undulately rugose surface. Onions occasionally ± bursting, inner scales more swollen than the outer ones, soon rotting. Many eelworms inside the galls. Allium spp.: Ditylenchus dipsaci

3a Galls distinct from the outside => 4

3b The externally normal leaves of A. senescens show rows of chambers in the locally more compact parenchyma, each containing a single larva. Larvae white to yellow. Unidentified gall midge

4a Bulges of minor or larger expansion, with black spore balls inside; at first lead-grey translucent, then with black spore dust when broken open => 5

4b Flat, 1.5–5 mm broad, brown-red bulges on leaves, scapes and sheaths of inflorescences. A. schoenoprasum: Physoderma allii

4c The plant elongates above the bulb. Cultivated Allium spp.: Peronospora destructor

5a Leaves of young plants, also bulb scales, with one to several stripes, about 10–20 mm long, bulging, bluish-green, later-on with black dusting of smut spores. Allium spp.: Urocystis cepulae

5b Yellow spots on ± disfigured leaves. Allium spp.: Puccinia allii

5c Spermogonia on both sides leaf, orange, often visible between the aecia. Aecia on underside leaf, in loose, often circular clusters on large, irregular, yellow spots; cup-shaped, with a white peridium and an orange mass of spores. Allium spp.: Puccinia sessilis

1a On vegetative parts => 2

1b Capitula greatly enlarged, bell-shaped, up to 10 mm long and 4 mm thick; receptacle spongy, swollen. A. alliariae: Unidentified tephritid fly

Galls callus-like, with sori of rust fungi => 4

2b Leaf blades bent and curled => 3

3a Leaf blades over large areas or completely curled. A. alpina: Unidentified aphid

3b Additionally, the bright yellow to yellow-green facultative gall causer, known from many host species. A. alliariae: Brachycaudus helichrysi

3c Leaf blade strongly recurved, strongly curled and dark green close to the froth covered froth-covered nymph. A. alpina: Philaenus spumarius

4a Leaf blade on underside with small, rotund, compact, brownish swellings, covered with 2-celled telia. A. alliariae, alpina, leucophylla: Puccinia expansa

4b Weak, ± extended, usually yellow-bordered, densely covered with aecia cushions or callus on the leaf undersides of A. alliariae, alpina: Uromyces veratri

1a On parts above ground => 3

1b Galls on roots => 2

2a Main- and side roots often with many fleshy nodules, up to about 7 mm long and 4 mm broad, oblong-oval, or at proximal part flattened and ± subdivided, laterally inserted. Coronilla spp.; Securigera spp.: Rhizobium leguminosarum

20b Irregular rotund, little galls on main root with central larval chamber. Each gall contains a single beetle larva. C. scorpioides: Catapion pubescens

3a On stems, buds or fruits => 6

3b On leaves => 4

4a Leaf blade folded or rolled inwards, caused by animals => 5

4b Internodes of completely diseased young shoots elongated; petioles and midrib ± thickened; leaf blades reduced, thickened, soon covered with grey-violet down of branched conidiophores on underside, Coronilla coronata, repanda subsp. dura, scorpioides; Securigera varia: Peronospora coronillae

5a Leaflets folded pod-like on midrib, the middle part especially strongly thickened. Securigera varia: Unidentified gall midge

5b Pale, indistinct pod-like folds of leaf blades of Securigera varia: Unidentified thrips

5c Leaflets twisted, folded, rolled inwards at margin. Coronilla coronata, Securigera varia: Aculus coronillae

5d Malformation of leaves and/ or inflorescences, flowers. Coronilla valentina subsp. glauca + pentaphylla: Hemitrichapion andalusicum

6a Midge galls in axillary buds or in pods => 7

6b Basal stem parts with ± expanded, often curved, bulging swellings, with single- or several rimmed depressions. Coronilla spp.; Securigera spp.: Planchonia arabidis

7a Pods disfigured => 10

7b Malformation of vegetative tissues => 8

8a Gall cavity absent, or if present, not covered with mycelium => 9

8b Gall cavity lined with mycelium. Leaf axil with bud-like gall, mainly arising from the fleshy thickened lower part of petiole and enlarged stipules. Inner wall with mycelium. Containing a single larva. Coronilla minima: Asphondylia coronillae

9a Irregular clusters consisting of hypertrophied leaflets, terminally on stem, rotund or egg-shaped, of variable size (averaging 8–9 x 7–8 mm), succulent, green- or pink-coloured. Containing several red, dull midge larvae. Coronilla juncea, valentina subsp. glauca: Dasineura coronillae

9b Leaflets pod-like swollen. Larvae glossy and jumping. Securigera varia: Contarinia coronillae

10a Pod with rotund to egg-shaped swelling. Inner wall with mycelium. Containing a single larva. Coronilla coronata, minima; Securigera varia: Asphondylia baudysi

10b Locally ± globularly swollen pods. Coronilla minima: Asphondylia coronillae

1a On leaves and stems => 2

1b Roots with slender spindle-shaped or cylindrical galls, up to about 4 mm long, bearing several side roots. S. oleracea: Meloidogyne hapla

1c Malformations known from many hosts as “leafy galls” on young spinach plants of S. oleracea, are caused by the widely distributed bacterium Rhodococcus fascians

2a Malformations caused by aphids or spittlebugs => 4

2b Malformations caused by eelworms or fungi => 3

3a Main venation as well as petioles spongy swollen; galls pale-green, ± largely encroaching into locally similarly disfigured and lacerate leaf blade. S. oleracea: Ditylenchus dipsaci

3b Developing leaves ± stunted; with yellowish-green, hunch-backed swellings and loose rolling of leaf margin. Diseased parts thickened, ± yellow-green, brittle; covered on underside with a dense, violet-grey down of branched conidiophores. S. oleracea: Peronospora farinosa

4a Malformations bearing aphids => 5

4b Malformation with conspicuous localised stunting and bending of midrib; leaf blade close to infestation deeper green; undulately lacerate and hunch-backed curled. S. oleracea: Philaenus spumarius

5a Aphids without conspicuous wax secretion => 6

5b Aphid with white-grey wax secretion. Leaf blades mainly with local, ± discoloured folds close to tip or margin, containing aphids. S. oleracea: Hayhurstia atriplicis

6a Aphid about 2.5 mm long, dull black. S. oleracea: Aphis fabae

6b Aphid 1–1.5 mm long, yellow or light- to yellow-green. S. oleracea: Aphis nasturtii

1a Galls on stems and leaves => 2

1b Receptacle hardened, partially deformed into a bulging, tough-walled, short, conical to egg-shaped gall. One larva per chamber. S. tinctoria: Trupanea stellata and/or Urophora spoliata

1c Galls located at the base of the flower head, unilocular, ovate, thin-walled, up to 1.5 mm in length; usually the flower head is not malformed and enlarged, galls inconspicuous externally Klasea radiata, Serratula coronata: Aulacidea serratulae

1d Galls in flower heads. Klasea erucifolia, lycopifolia, nudicaulis, radiata:
Isocolus serratulae

1e Galls in flower heads, without symptoms of external deformation. Serratula spp.: Phanacis eugeniae

2a Galls in the shoot tips => 7

2b Leaves with localised or expanded malformations, which may extend into the stems => 3

3a Wart-shaped rotund or spindle-shaped swellings caused by fungi => 5

3b Expanded, glabrous or pubescent malformations caused by animal inducers => 4

4a Leaves curved at the tip, leaf blade curled, the margin ± curved downwards. Sometimes on several similarly malformed leaves terminally clustered on ± shortened internodes. S. tinctoria: Philaenus spumarius

4b More or less conspicuously stunted leaves with curved, curled or bulge-like swollen leaf blades; leaf tips often rolled. Rolls either glabrous or, like the leaf blades, with spotted, striped white or reddish erinea. S. tinctoria: Aculus rigidus

4c Conspicuous spindle-shaped galls, about 8 x 3 mm long, on petioles, also on midribs, to a lesser extent on lateral veins of the leaf blade of S. tinctorial: Loewiola serratulae

4d Lignified but relatively soft stem deformation, differently shaped, which depends on the number of larval chambers. Klasea erucifolia: Aulacidea ascanica

5a Malformations with fruiting fungal sori on the surface => 6

5b Galls hardly 1 mm long, multicellular, wart-shaped, ± golden yellow translucent; many on the underside of basal leaves. S. tinctoria: Synchytrium aureum

6a Leaf blade with rotund spindle-shaped swellings, up to 8 mm long, on the venation, usually conspicuous yellow or red margined, on the underside sometimes weakly arched, with cylindrical cup-shaped aecia occupied sori. S. coronate, tinctoria: Puccinia schroeteriana

6b Slightly bulging swellings on the midribs, less often on the lateral veins; occupied by bright brown uredinia. S. coronata, tinctorial: Puccinia hieracii

6c In SE-, C-Eu; with similar biology on Klasea bulgarica, lycopifolia, radiata; Serratula coronata, tinctoria: Puccinia schirajewski

7a Galls at the shoot tips => 8

7b Shoot terminally with spindle-shaped swelling. In the pith is a single caterpillar. S. tinctoria: Eucosma albidulana

8a Leaves on the shoot tip transformed into an erect, up to 15 mm long, cone-shaped pale gall. Several red larvae. S. tinctoria: Unidentified gall midge

8b More or less rosette- or sometimes almost bud-shaped clustering of leaves on stunted shoot tips. Infected organs often with conspicuously white or reddish pubescence. S. tinctoria: Aculus rigidus

1a On roots or root collar => 4

1b On stems or leaves => 2

2a On leaf blade or -stalk => 3

2b Stem with spongy, pale green swelling; leaves stunted and ± curled. P. vulgaris: Ditylenchus dipsaci

3a Leaves loosely deflected at margin, slightly discoloured and curled, caused by black aphids. P. vulgaris: Aphis fabae

3b Minor hypertrophies on leaf axis, occasionally also slight arching of infected, usually pale green parts of leaf blade. Caused by a mycelium developing spermogonia and aecia. P. acutifolius, coccineus, vulgaris: Uromyces appendiculatus

4a Malformations on root => 5

4b Compact, succulent, mainly one-sided proliferations on root collar. “Root cancer*. P. vulgaris: Agrobacterium tumefaciens

5a Roots with distinctly protruding galls => 6

5b Roots not changed from the outside; inside with giant cells; temporarily bearing ± lemon-shaped lighter to darker egg capsules. Phaseolus vulgaris: Heterodera sp.

6a Nodular swellings, often occupying all sides of the complete root body, bearing several side roots. Phaseolus vulgaris: Meloidogyne hapla

6b Globular or egg-shaped nodules, up to about 5 mm long, inserted laterally, usually many and occasionally clustered. Phaseolus vulgaris: Rhizobium phaseoli

1a On above ground parts => 3

1b On roots => 2

2a Nodular or spindle-shaped swellings. M. officinalis: Meloidogyne hapla

2b Globular or up to 8 mm long, cylindrical, forked or coral-like branched nodules. Melilotus spp.: Sinorhizobium meliloti

3a On inflorescences, flowers or fruits => 9

3b On vegetative organs => 4

4a On shoot axis or leaves of fully developed plants => 5

4b Young plants considerably stunted. Stems shortened, spongy, thickened. Leaves clustered, occasionally the axial parts swollen, leaf blades distorted. Melilotus spp.: Ditylenchus dipsaci

5a On shoot axis => 7

5b On leaves => 6

6a Leaflets folded upwards, halves at base ± adnate and swollen, together with midrib, into a globular or oblong gall, up to 6 mm long, protruding on underside. Containing a yellowish beetle larva. M. albus, altissimus, dentatus, officinalis: Tychius crassirostris

6b Weaker swelling of midrib of leaflet. Containing a single larva. M. albus, altissimus, officinalis: Tychius meliloti

7a Inducer inside the gall => 8

7b Acuminate-rotund- to oblong oval, often snapped off, or ± bent, expanded bulging swellings of stem, containing in rimmed depressions the inducer. M. dentatus, officinalis: Planchonia arabidis

8a Rotund to spindle-shaped swelling, 5–15 mm long. The pith containing a maggot. M. albus, dentatus, officinalis: Melanagromyza submetallescens

8b Weak swelling, inside a compact pith containing several white larvae. M. albus: Unidentified dipteran

9a All flowers of a plant occasionally disfigured and ± pubescent. Calyx hardly disfigured, corolla and anthers often reduced, ovary developing into a short, leafy cone, transformed together with the axils of stipules, developing shoots into a ± dense leafy inflorescence. M. albus, altissimus, dentatus, officinalis: Unidentified gall mite

9b Flower buds swollen, unopened. M. altissimus, officinalis: Contarinia sp.

9c Flowers strongly greened; beetle larva living inside stem just below inflorescence. M. albus, altissimus, dentatus, officinalis: Stenopterapion meliloti

9d Beetle larvae feed within the pod on the developing seed; this may cause some galling of the pods. M. albus, ? altissimus, officinalis: Tychius breviusculus

1a On parts above ground => 2

1b Roots with nodular, compact swellings. L. salicaria: Meloidogyne hapla

1c Swelling in root; containing a chamber with a weevil larva. L. salicaria: Hylobius transversovittatus

2a Malformations on various vegetative as well as generative parts => 5

2b Globular to spindle-shaped galls on shoot axis => 3

3a Galls caused by weevils. In the gall a legless, curved weevil larva => 4

3b Weak, oblong swellings close to shoot tip. L. salicaria: Unidentified gall midge

4a Long spindle-shaped or rotund swelling, usually one-sided, succulent, one- or more-chambered on lower parts of shoot axis. Apically organs sometimes severely stunted. L. hyssopifolia, ? salicaria: Nanomimus hemisphaericus

4b In similar one- or more-chambered galls. L. hyssopifolia, salicaria: Nanomimus circumscriptus

4c Side shoots with a swelling, up to 8 mm long, rotund-oval, one-chambered. Containing a single larva. L. portula: Dieckmanniellus gracilis

4d Slender spindle-shaped stem galls, 12–18 mm long, usually at leaf insertions of several L. hyssopifolia, junceum, salicaria: Dieckmanniellus nitidulus and/or D. helveticus

4e Small conspicuous swelling of stem, laterally protruding, variously expanded. L. acutangulum, hyssopifolia, salicaria: Nanophyes globiformis

4f Inconspicuous swelling of the stem. L. salicaria: Nanophyes rubricus

5a Malformations mainly involve unfolded leaves => 6

5b Lateral buds or tips of vegetative shoots disfigured. All leaves of infected axillary buds severely stunted, adnate at base, developing into a gall up to 6 mm long, ± reddened with free terminating apex over differing length. Infestation of shoot tip results in stunting of axial parts with tuft-like clustering of basally largely stunted leaves. Infected flower buds swollen at base; calyx hardened. Stunting of all other parts; usually unopened. Depending on gall size a single or several orange-yellow larvae. L. salicaria: Bayeriola salicariae

6a Malformations caused by aphids or spittlebugs => 7

6b Petioles swollen over a length of about 10 (15) mm, slender pear-shaped. Galls succulent, one-chambered. Leaf blades severely stunted. Containing a single larva. L. hyssopifolia, salicaria: Nanomimus circumscriptus

6c Minor swellings of leaf. L. portula: Chlorochytrium rubrum

7a Malformations caused by aphids => 8

7b Leaf blade deflected, curled, locally deep green; infestation close to shoot tip results in one-sided stunting and distortion of axial parts, associated with clustering of similarly disfigured leaves. L. salicaria: Philaenus spumarius

8a Clustering of disfigured leaves or also failed flowers on ± stunted shoot tips caused by aphids, about 2 mm long, pale to yellowish-green. L. hyssopifolia, salicaria, virgatum: Myzus lythri

b8 Clustering of ± stunted, deflected and curled leaves on less stunted shoot tips or similar malformations on several lower situated leaves caused by black aphids. L. salicaria: Aphis fabae

1a Flower galls => 17

1b On stems, shoot tips, buds or leaves => 2

= Root galls of Meloidogyne hapla are known from Teucrium

2a Localised or expanded galls restricted to the leaf blades of single or several leaves => 13

2b On shoot tips, terminal leaves, buds or stems => 3

3a On buds or on tips, terminally on shoots => 8

3b On stems, partially encroaching into lateral leaves and buds => 4

4a The causers live, and/or fruit inside the galls => 7

4b The animal causers live on the outside of the galls or fungi develop their fruiting bodies on the outside => 5

5a Malformations expanded, slender and elongate, of irregular shape, large parts covered with dark-brown telia at maturity => 6

5b Mainly basal part of stem with spindle-shaped to irregularly bulging, often distorted swellings which contain in a single or several rimmed depressions single froth-covered nymphs. Teucrium spp.: Planchonia arabidis

6a The ± dusty, black-brown sori develop on stems, sometimes also on petioles, as well as on leaf undersides, ± disfiguring the organs. T. montanum, orientale: Puccinia constricta

6b Sori similar, black. Gall-like malformations facultative, rare, of variable shape. Diseased shoots sometimes with extensive sori, occasionally distorted and curved, sometimes almost witches’ broom-like disfigurations, usually sterile. Teucrium spp.: Puccinia polii

7a Irregular, compact swellings or proliferations on root collar or stem base on one side or enveloping the stem. Black spore masses develop inside the galls. T. montanum: Melanotaenium jaapii

7b Only a few swellings, ± irregular spindle-shaped or nodule-like, up to 10 mm long. Shoot necrotic above gall. Containing single to many larvae. T. fruticans, scorodonia: Thamnurgus kaltenbachii

8a On shoot tips or lateral buds => 12

8b On several leaves terminally, usually on only slightly stunted shoots => 9

9a Malformations caused by gall mites => 11

9b Malformations caused by aphids or spittlebugs => 10

10a Leaves on shortened shoot tips clustered into loose, almost cone-like galls. Teucrium spp.: Aphis teucrii

10b Stem terminally ± distorted and curved over ± 3 internodes, leaves inserted nest-like, converging, curled, locally dark-green. T. scordium, scorodonia: Philaenus spumarius

11a Plants usually excessively branched. Leaves disfigured. T. montanum: Unidentified gall mite

11b Leaves and stem on sometimes shortened tip of vegetative shoots with densely felt-like pubescence. T. scorodonia: Unidentified gall mite

12a Buds on main- and side shoots compact. Outside leaves almost normal, arranged artichoke-like, the inside ones bear single to several orange-red larvae. T. capitatum & subsp. lusitanicum, chamaedrys, salviastrum, scorodonia: Dasineura teucrii

12b Leaves clustered terminally on ± stunted shoots, thickened, disfigured, forming densely pubescent tufts. T. scorodonia: Unidentified gall midge

13a Leaves often with yellowish bulges in the leaf blades, rotund, protruding on underside; on venation or stalks ± spindle-shaped to oblong-oval, soon covered with sori densely covered with brownish telia => 16

13b Malformations without externally protruding sori of fungus => 14

14a Galls a few mm across, pustule- or wart- shaped or ± oblong-oval => 15

14b Leaf blade twisted and curled. Containing many larvae. T. chamaedrys: Unidentified gall midge

15a Leaf blades, especially of the middle and upper stem leaves, with many uneven bulges, protruding at upperside, often situated along the margins; pale yellow on upperside, sometimes ± strongly pubescent; open on underside, inside with emergentia or strong abnormal pubescence T. capitatum subsp. gracillimum, chamaedrys, murcicum, scordium: Aculus teucrii

15b Leaf blades of basal leaves with many swellings, mainly protruding on underside, 1–3 mm long, at first yellowish-green, later on almost black-brown, ± pock-like. Sometimes joined into dense groups on the ± curved veins or stalks; more rarely in the bark of lower stem parts. T. scorodonia: Physoderma vagans

16a Sori with grey-brown spores, often many; arched on the underside of leaves; on upperside often ± depressed; occasionally causing distortions of axial parts of younger leaves. More rarely but then similarly on stems. T. botrys, chamaedrys, pyrenacium: Puccinia chamaedryos

16b Similar pads or bulges, causing conspicuous distortions on axial parts. Teucrium spp.: Puccinia annularis

17a Malformations of flowers caused by gall midge larvae => 19

17b Galls caused by lacebugs => 18

18a Corolla weakly thickened, especially upper part slightly enlarged, unopened, stamens and sometimes pistil weakly swollen. T. canum, chamaedrys, polium, scorodonia: Copium clavicorne

18b Flower swollen up to two or three times the normal size. Corolla strongly swollen, especially at base. Calyx disfigured, lacerated, ± thickened, yellowish. Stamens and pistil ± stunted. Gland hairs abnormally enlarged. T. capitatum & subsp. gracillimum, gnaphalodes, montanum, polium: Copium teucrii

19a Galls on T. scordium or scorodonia => 20

19b On T. montanum. Flower disfigured. Corolla inflated, bladder-like. Unidentified gall midge

20a On T. scordium. Flower swollen, unopened. Containing a single larva.
Unidentified gall midge

2b On T. scorodonia. Flowers clustered, enlarged, unopened. Ovary almost capsule-like, stalked, enlarged, pubescent. Pistil shortened. Unidentified gall midge

1a On tips of main and side shoots, on male flower buds or on needles => 5

1b On stem parts, branches or twigs => 2

1c Orange-red larvae develop in cones of L. decidua, x polonica: Resseliella skuhravyorum

2a On older stem parts or on thicker branches => 4

2b On thinner twigs => 3

3a Oblong or often nodule-shaped, cherry- to hazelnut-size swelling on younger stems or twigs, often at the base of a branching and ± covered with a grey resin blister. L. decidua: Cydia zebeana

3b Elongate resinous swelling about twice stem width at its widest; soft and spongy, becoming hard and woody after adult emerges in May, June. Containing caterpillar for 22 months from June onwards, pupa April, May second year. L. decidua: Cydia millenniana

3c Bark of twigs with small swellings, pubescent inside. L. decidua: Trisetacus laricis

4a Long club-shaped swelling on stems and branches, bearing a bush of mistletoe. L. kaempferi: Viscum album

4b Scurfy, cracked, ± dark coloured, 15–40 cm long patches of bark ± deeply depressed, rimmed at margin with resin reacting with cancers on at first sometimes swollen parts of branches, occasionally also on the stems. Infections starting from 2–4 year old branches. L. decidua: Lachnellula willkommii

5a On the tips or short- and long shoots, also on male flower bud => 7

5b Needles slightly thickened, discoloured, almost bent over at right angles; an aphid present at the bending point => 6

6a Aphid dark brown to black, naked or covered with wax flakes. L. decidua, x eurolepis, gmelinii, kaempferi, laricina, lyallii, sibirica: Adelges laricis

6b Aphid yellow-green to dark green, without wax cover, only slightly frosted. L. decidua, x eurolepis, kaempferi, sibirica: Sacchiphantes viridis

6c To the same species group belongs the anholocyclic (only asexual females known), only on Larix spp. living: Sacchiphantes segregis

7a Tips of previous year’s short shoots swollen ± hemispherically. Galls up to pea-size, also the male flower buds occasionally transformed to similar, more or less egg-shaped, usually larger galls. Galls to August with brown scales, covered later on at first with bright fluid, then white crumbly resin, driving neighbouring needles widely apart, star-like. Containing a single brick-red larva in the upper part of the gall. L. decidua, occidentalis: Dasineura kellneri

7b Similar, globular to oblong-egg-shaped brown galls; often also on terminal buds of long shoots; in contrast with the previous midge galls, which may also be present, always dry, lacking a resin cover. L. decidua: Trisetacus laricis

1a On plant parts above ground => 2

1b Roots with slender spindle-shaped swellings, up to 5 mm long. T. aquilegiifolium, simplex: Meloidogyne hapla

2a On inflorescences, flowers or fruits => 17

2b On stems, shoots and leaves => 3

3a Malformations mainly on stem, or usually involving many severely stunted leaves, clustered at shoot tips, or extending over many leaflets of largely disfigured leaves => 12

3b Galls mostly on unfolded leaves; locally restricted, usually wart- or spindle-shaped. Caused by fungi => 4

4a Galls several mm long, in the leaf blades ± rotund, protruding on underside; on leaf veins, -midrib, -stalk, or flower parts spindle-shaped to oblong-oval. Bulges with sori of black telia or with densely positioned, yellowish aecia => 5

4b Galls wart-shaped, multi-cellular, up to 1 mm long, golden-yellow; single or ± coalescing, usually on underside of basal leaves, also on axis, stalks and basal stem parts. T. alpinum, flavum, lucidum, simplex, squarrosum: Synchytrium aureum

5a Bulges on leaves usually downwardly arched and predominantly only there bearing aecia; on upper side usually ± depressed, partially bearing spermogonia, often ± crimson to violet-red margined => 6

5b Sori on leaf underside, also on stem; of variable size, often conspicuous, slightly arched, black, weakly glossy, compact. T. alpinum: Puccinia rhytismoides

6a Aecia densely positioned, in smaller or larger groups on underside of ± arched bulges. Several, especially biologically different rust fungi, alternating on grasses, indistinguishable by their galls and usually also by the microscopic morphology of their aecia => 8

6b Aecia positioned loosely => 7

7a Aecia positioned on expanded, thickened, often dark violet discoloured spots, usually on both sides. Peridium usually with deflected border. Spermogonia develop rarely. T. alpinum: Puccinia septentrionalis

= On same host, with similar distribution, alternating on Agrostis, the rust fungus Puccinia recondita develops only in low number (8–12) in dense groups on underside leaf; aecia occur on discoloured, not noticeably thickened spots.

7b Aecia on often yellow-brown discoloured, hardly swollen leaf spots, protruding on underside, associated with honey-coloured spermogonia, developing on both sides. Peridium cup-shaped, with deflected, lacerate border. T. foetidum: Puccinia thalictri-koeleriae

8a Frequent fungi with aecia on several Thalictrum species => 11

8b More locally recorded fungi, which develop aecia on only a few species => 9

9a Aecia with several Thalictrum species as main host => 10

9b Aecia on T. foetidum as main host; in rounded groups on leaf underside, also occurring on fruits and in elongated patches on disfigured leaf midrib, -stalk and stem. Peridium cup-shaped or ± cylindrical, with lacerate white border: Puccinia thalictri-distichophylli

10a Aecia with cup-shaped or funnel- to tube-shaped peridium, at maturity with deflected, ± frayed border. T. aquilegiifolium, foetidum, minus: Puccinia poae-nemoralis

10b Aecia not further described, on T. aquilegiifolium, minus: Puccinia elymi

11a Aecia in smaller or larger groups on slightly thickened spots, often violet-brown on upperside, on underside yellowish and usually brown-bordered. Peridium cup-shaped, with deflected, frayed border. Thalictrum spp.: Puccinia alternans

11b Aecia and the often conspicuous spermogonia, positioned in a circle, usually developing on upperside on often distinctly swollen pads. Peridium whitish or yellowish with deflected, irregularly serrate or slightly fringed border. T. flavum, minus, simplex: Puccinia recondita species complex

12a Differently furnished malformations caused by animal parasites => 14

12b Malformations bearing early brown sori or exhibiting at first ± lead-grey bulges, with dusting of black spores later on => 13

13a Lead-grey swollen bulges, occurring on the often largely stunted leaf blades especially on venation protruding on both sides, often also on the ± bent leaf-midrib, -stalk, on stems and even flower parts. At first closed, later on erupting and with black dusting. Thalictrum spp.: Urocystis sorosporioides

13b Mycelium perennial, the developing host organs changing considerably. Shoots with lanky, elongated internodes, developing faster than normal ones. Leaf axis squat, leaf blade narrower and pale, diseased parts bearing many dark-brown telia. Thalictrum spp.: Tranzschelia anemones

14a Mainly curling or slightly swollen malformations of ± stunted leaves => 15

14b Leaflets curled, margin folded upwards, forming a subglobular gall of variable size. Containing several reddish larvae. T. speciosissimum: Dasineura bragancae

15a Malformations not conspicuously pubescent => 16

15b Up to 10 mm long, bud-like clustering of markedly stunted, ± whitish haired leaves on tips of main- and side shoots or in stunted axillary buds on the longitudinal growth. Larvae glossy red. T. aquilegiifolium, flavum, minus, simplex: Jaapiella thalictri

16a Malformations of terminal leaves and possibly of neighbouring inflorescences caused by midges or aphids => 17

16b Leaf blades of usually basal leaves on the ± stunted midrib converging. Leaflets shortened, mostly spoon-like, converging, thickened, strongly rugose and curled. T. flexuosum, minus: Phyllocoptes jaapi

16c A few internodes of apical part of stem stunted, bent when infestation is one-sided. Leaves and sometimes stem of the similarly stunted and disfigured inflorescence variously clustered. Leaf blades ± converging, curved and curled, dark green close to infestation site. Thalictrum spp.: Philaenus spumarius

17a On inflorescences or single flowers => 18

17b Fruit distinctly swollen, globular or acuminated, egg-shaped, up to 5 mm long, seeds absent; wall succulent, thickened; gall in dry condition ribbed. Containing one or two yellow larvae. T. aquilegiifolium, flavum, lucidum, minus incl. subsp . majus, simplex, speciosissimum: Ametrodiplosis thalictricola

18a Malformation of inflorescence or galls on single or clustered flowers; caused by animal inducers => 19

18b Expanded or localised malformations in the axis of the panicle, flower peduncles or perianth leaves caused by fungi => 5

19a Single flowers globularly swollen, stamens and especially anthers little developed; sometimes on shortened stalks and axis of panicle with several clustered in the otherwise normally flowering or already fruiting inflorescences. Larvae glossy red. T. aquilegiifolium, flavum, minus, simplex: Jaapiella thalictri

19b Inflorescence markedly stunted, densely occupied by disfigured, ± greened flowers. T. aquilegiifolium, alpinum, delavayi, flavum, lucidum, minus: Aphis thalictri

1a On parts above ground => 4

1b On root collar or on roots => 2

2a On roots => 3

2b Rotund swellings on root collar, up to 6 mm long one-chambered. Containing a single larva. T. arvense, Noccaea perfoliata: Ceutorhynchus assimilis

2c Rotund root collar galls, 3–5 mm long. Noccaea perfoliata: Ceutorhynchus carinatus

3a Conspicuous, spindle-shaped or cylindrical thick-succulent compact galls, often more than 10 mm long, on main- and side roots, often in smaller sizes on secondary roots. “Clubroot”. Thlaspi spp.: Plasmodiophora brassicae

3b Roots often with many slender, 2–4 mm long cylindrical swellings, provided with several lateral roots. T. arvense, Noccaea brachypetala: Meloidogyne hapla

= Cyst eelworms, both Heterodera cruciferae and H. schachtii have been reported from T. arvense

4a Malformations of indefinite shape extending over several organs or localised to extensive malformations caused by fungi fruiting at surface, sori of which usually occur simultaneously on several organs => 8

4b Locally definite galls of rather similar shape on single organs => 5

5a On inflorescences, flowers or fruits => 17

5b On stems or leaves => 6

6a Galls conspicuous, spindle-shaped or globular => 7

6b Galls wart-shaped, less than 1 mm across, usually many on the underside of basal leaves. Sometimes ± coalesced crust-like; also on petioles and basal parts of young stems. T. rotundifolium: Synchytrium infestans

7a Galls ± globular to acuminated, spindle-shaped, about 5–6 mm long. Containing a single larva. Noccaea perfoliata: Ceutorhynchus carinatus

7b Spindle-shaped glabrous galls, about 20–25 (35) mm long, usually on all sides of stems, sometimes almost node-like, on petioles or midrib ± flattened; especially on leaves also deep green inside; partially with rather long tunneled channels. Containing a single larva. T. arvense, Noccaea brachypetala, perfoliata: Ceutorhynchus chalybaeus

8a On the malformations develop white or brown fruiting bodies of fungi => 14

8b Malformations caused by animals => 9

9a The animals develop outside on the galls, partially distinctly visible, partially hidden by the malformation => 10

9b Young plants largely stunted. Hypocotyls, petiole, and leaf blade base shortened, pale green, spongy. Neighbouring shoots severely stunted and thickened. Later infected stems are swollen over different lengths on one- or all sides, shortened, occasionally bent. Galls at surface undulately wrinkled, ± necrotic, with many eelworms inside. Thlaspi spp.: Ditylenchus dipsaci

10a Malformations caused by aphids or spittlebugs => 12

10b Malformations caused by larvae of gall midges => 11

11a Leaves terminally or laterally on stunted shoots, also in axillary buds ± tuft-like clustered, stunted, thickened at base and discoloured. Primordia of inflorescence are included in the gall, or display densely clustered, severely disfigured buds. Between the organs develop whitish or yellowish-white, jumping larvae. T. arvense: Contarinia nasturtii

11b Shoot tip disfigured. T. montanum: Unidentified gall midge

12a Malformations caused by aphids => 13

12b Young stems stunted and bent over a few internodes. Inserted leaves stunted, ± nest-like converging, undulately curled, locally dark green. T. arvense, Noccaea brachypetala: Philaenus spumarius

13a Tips of vegetative or generative shoots stunted; organs clustered, severely stunted. Aphid 1.5–2 mm long, grey-green to grey-yellow, siphunculi yellow, twice as long as the oblong yellow-green cauda. T. arvense: Lipaphis erysimi

13b Similar malformations, mainly restricted to the tips of shoots or inflorescences on severely disfigured leaves and flower buds, and on fruits and younger parts. Aphid 2–2.5 mm long, yellow-green, with 2 longitudinal rows of small black cross stripes; densely grey powdered; siphunculi short, swollen, brownish-black, about as long as the oblong, dark-green cauda. T. arvense: Brevicoryne brassicae

14a Sori white; infestation very variable, often without distinct malformations => 15

14b Mycelium disfigures the infected shoots completely or in the terminal parts, which bear smaller, thickened, paler leaves and which usually remain sterile. Exceptionally developing flowers are largely disfigured and ± greened. On expanded parts mainly of the leaf undersides develop many punctiform sori with rust- to dark-brown telia. T. alliaceum, arvense, “bulbosum”; Noccaea spp.: Puccinia thlaspeos

15a The sori protruding from the malformations consist of branched conidiophores => 16

15b Sori consist of dense pads, at first closed, glossy, porcelain-like, later on rupturing and with mealy dusting, usually with several, which are rotund on leaf blade underside, ± oblong oval to spindle-shaped and occasionally bent on leaf veins, – stalks and stem parts. T. arvense; Noccaea caerulescens, perfoliata: Albugo candida

16a Infected stem parts pale green, hypertrophied and ± distorted; sometimes slightly swollen during the development of infected leaves. On infected axial parts inserted organs, especially flower buds, severely stunted; diseased siliques usually crippled, occasionally enlarged and swollen. T. arvense: Hyaloperonospora thlaspeos-arvensis

16b On Noccaea brachypetala, caerulescens, causing similar damage: Peronospora thlaspeos-alpestris

16c Similar malformations on Noccaea perfoliata: Hyaloperonospora thlaspeos-perfoliati

17a Galls on single or several flowers or fruits => 18

17b Internodes of inflorescence distinctly shortened. Buds, flowers or young siliques clustered. Flowers partially ± greened. T. arvense: Thrips tabaci

18a Malformations usually inconspicuous, without involvement of other organs, on older ovaries or fruits => 20

18b Flower galls => 19

19a Already largely developed, single or sometimes clustered flower buds strongly swollen, almost globular. Larvae inside the organs or also between densely clustered flower buds; white to pale yellow, jumping. T. arvense; Noccaea brachypetala, caerulescens: Contarinia nasturtii

19b Calyx of opened flowers strongly hypertrophied. Corolla and the broadened stamens ± greened. Ovary severely disfigured, narrowed and elongate. Locally oblong-oval white sori on the diseased organs. T. arvense; Noccaea caerulescens, perfoliata: Albugo candida

20a In largely developed shoots, not or only slightly swollen, develop ivory white to lemon yellow coloured, jumping midge larvae. T. arvense: Contarinia thlaspeos

20b In the seed primordia of hardly disfigured fruits develop yellow-brown to grey-violet spore masses. Noccaea brachypetala, caerulescens, crantzii: Thecaphora thlaspeos

1a On parts above ground => 2

1b Roots with small nodular to spindle-shaped swellings. Convolvulus sp.:
Meloidogyne hapla

2a On shoots and leaves => 3

2b vary, and also capsules, in usually conspicuously smaller flowers hardly changed; sometimes remarkably narrowed in apical part; anthers almost always sessile, swollen, at first like the nectar ring temporarily bearing whitish to yellowish sori containing conidia. Spores in balls, pale brown-red; mainly in several or all, at first slightly swollen, later on aborted seed primordia. Convolvulus arvensis, Calystegia sepium, soldanella: Thecaphora seminis-convolvuli

3a Malformations caused by aphids, psyllids or spittlebugs => 7

3b Malformations caused by different inducers => 4

4a Galls caused by parasitic animals => 5

4b Usually aecia arranged in a circle on the underside of undisfigured leaves. Sori on veins, stalks and axial shoot parts sometimes slightly swollen. Convolvulus spp.; Calystegia spp.: Puccinia convolvuli

4c Stems with a white cover, at first shiny, later powdery. Parts of the plant may become disfigured. C. pentapetaloides, siculus, tricolor: Albugo convolvulacearum

5a Malformation of many terminal leaves => 6

5b Shoots or petioles with ± expanded swellings on all- or one-side, pale green, spongy, on surface ± wrinkled. Leaves ± distorted. Convolvulus arvensis: Ditylenchus dipsaci

6a Terminal shoots or plant completely and severely stunted, axial parts shortened; leaf blades folded upwards, variously curved and rolled loosely, swollen, yellowish or crimson discoloured, abnormally, ± densely pubescent. Convolvulus althaeoides, arvensis, cantabrica, thunbergii: Aceria convolvuli

6b Similar, but glabrous malformations usually without distinct stunting of shoots, on loosely arranged, ± erectly folded and sickle-shaped disfigured leaves. Convolvulus arvensis: Aculus convolvuli and or Aceria malherbae, the latter also on Calystegia sepium

7a Malformations of often numerous leaves on shoots. Caused by aphids => 8

7b Leaves on the distinctly shortened terminal internodes clustered and stunted, with several converging ± nest-like; leaf blades partially distorted and deep green. Contain a froth-covered nymph. Convolvulus arvensis, Calystegia sepium: Philaenus spumarius

7c Pustule, 2 mm across, protruding on both sides of leaf blade, with exit hole on leaf underside, surrounded by white hairs. Convolvulus canariensis: Unidentified psyllid

8a Leaves folded, partially rolled, ± curled; contain black aphid. Convolvulus arvensis, Calystegia sepium: Aphis fabae

8b Leaves curled, curved downwards. Aphid green. Convolvulus arvensis, Calystegia sepium: Myzus persicae

1a On above-ground parts => 2

1b Roots with slender, spindle-, club- or nodule-shaped swellings. B. tripartita: Meloidogyne hapla

2a On vegetative parts => 3

2b Tephritid larvae in flower heads. B. cernuus, tripartita: Dioxyna bidentis

3a Leaf blades with conspicuous ripples => 4

3b Basal leaves, especially on the underside of the leaf blades, with many golden-yellow translucent warts, less than 1 mm long, ± hemispherical. B. tripartita: Synchytrium aureum

4a Leaf blade areas in different ways ± loose nest-like, curved downwards. Strongly curled and dark green, especially close to the froth-covered nymph. Bidens spp.: Philaenus spumarius

4b Leaf blade partially at the margin loosely curved and curled downwards. B. cernuus, frondosus, pilosus, tripartitus: Brachycaudus helichrysi

1a On parts above ground => 4

1b On roots and root collar => 2

2a On root collar => 3

2b Side roots with usually 4–6 mm long, slender, spindle-shaped succulent swellings. Inside the galls cells contain masses of minute spores. Plasmodiophora brassicae

3a Rotund, up to 8 mm long one-chambered galls with a glabrous surface, contain a curved larva. Ceutorhynchus assimilis

3b Proliferations of conspicuous bulging, at surface ± subdivided, up to almost fist size galls, ± one-sided attached to the plant part. Agrobacterium tumefaciens

4a On flowers => 9

4b On stems or leaves => 5

5a Malformations caused by animals => 6

5b eaves on the underside with dense, rotund pads, sometimes in large numbers, rotund on the leaf blades, on the veins bulging, at first glossy, porcelain-like, later opening with mealy dusting of white sori. Albugo candida

5c Leaves somewhat disfigured with pale spots on the upperside, that correspond with a fungal bloom on the underside, consisting of erect, apical strongly branched conidiophores. Hyaloperonospora cochleariae

6a Galls predominate on petioles, leaf veins or on stems => 8

6b Malformations on expanded plant parts or on leaves => 7

7a Basal leaves of young plants loosely deflected over their length, ± curled. Many black aphids on underside. Inducer unidentified – ? aphid

7b Stems of younger main- or side shoots stunted, sometimes curved, leaves deflected, curled, their margins rolled inwards. Inflorescences stunted, flowers densely clustered ball-like. Contain a froth-covered nymph. Philaenus spumarius

8a Galls spindle-shaped, on leaves mainly on underside, 15–25 mm long, glabrous, also green inside, on midribs, petioles, more rarely on rather young stems. Containing a single larva. Ceutorhynchus chalybaeus

8b Spongy, at surface undulate-wrinkled, pale green swellings of variable length on stalks and lower part of midrib of basal leaves. Ditylenchus dipsaci

9a Flower buds strongly swollen, ± globular, about 5–7 mm across, unopened. Several, mainly yellow, non- jumping larvae. Dasineura armoraciae

9b Galls similar, but more slender and smaller, 2–4 mm long. Larvae whitish to pale yellow, jumping. Contarinia nasturtii

1a On parts above ground => 3

1b On roots => 2

2a Roots with 3–5 mm long, slender spindle-shaped swellings, situated on root body with primordia of adventitious roots. Anthyllis spp.: Meloidogyne hapla

2b On inflorescences, flowers or fruits => 3

3a On inflorescences, flowers or fruits => 7

3b On stems or leaves => 4

4a Galls larger than 1 mm => 5

4b Under 1 mm long wart-shaped, ± golden-yellow translucent galls in large numbers on underside of leaves; also on stems. A. vulneraria: Synchytrium aureum

5a Malformations caused by animals => 6

5b Petiole, rachis or midrib with yellowish sori of occasionally slightly gall-like swollen pads, about 1–3 mm long, oval, soon bearing spores, arched on underside. Anthyllis spp.: Uromyces anthyllidis

6a Longitudinal growth of plant stunted; sometimes strongly branched; stem at base spongy. Developing side shoots thickened and stunted as well, ± bushy, clustered. Leaves and stipules variously disfigured. A. vulneraria: Ditylenchus dipsaci

6b Stem with ± expanded spindle-shaped swelling; rind with rimmed groove-like depressions containing single froth-covered nymphs. A. vulneraria: Planchonia arabidis

6c Galls on leaf buds. A. cytisoides, polycephala: Asphondylia sp.

7a Malformations in flowers => 8

7b Beetle larvae feed within the pod on the developing seeds; this may cause some galling of the pods. A. vulneraria & subsp. polyphylla: Tychius schneideri and/or T. junceus

8a Several or single flowers slightly swollen at base, unopened. Larvae orange-coloured. A. vulneraria: Unidentified gall midge

8b Several or usually all flowers of an inflorescence completely disfigured, transformed into ± spiny-globular, densely whitish or yellowish-white pubescent balls. A. vulneraria: Unidentified gall mite

1a On flowers or inflorescences => 4

1b On stems and leaves => 2

2a Malformations in rosette or on base of young stem => 3

2b Leaf blade with conspicuous, rotund, yellowish to brown pads or distinctly arched, oblong-oval bulges, arched on underside, upper side ± depressed also on midribs or stalks of leaves as well as on young axial parts; soon bearing aecia and spermogonia. A. azurea, calcarea, capensis, leptophylla, ochroleuca, officinalis, undulata: Puccinia recondita

3a Rosettes additionally branched. All parts greatly shortened, swollen, transformed into a ± compact gall. A. caespitosa: Aphelenchoides fragariae and/or Rhodococcus fascians

3b Young stem parts ± severely stunted, sometimes slightly swollen at base. Containing a yellowish-white caterpillar; head and neck black. Anchusa spp.: Cynaeda dentalis

3c More frequent on Anchusa in inflated leaf mines, later on occasionally also in ± crippled, sometimes gall-like disfigured stems occurs the caterpillar of the very close Epascestria pustulalis

4a Malformations on flowers, without distinct involvement of inflorescence rachis => 6

4b Young inflorescences with shortened axial parts; bracts and flower primordia ± strongly clustered => 5

5a Flowers ± distorted, bracts curled, deflected. A. officinalis: Dictyla echii

5b In sometimes similar malformations on inflorescence with stunted axis, clustered, ± disfigured flowers, curled and curved bracts or also on similarly disfigured vegetative shoots. Anchusa spp.: Philaenus spumarius

5c Flowers distorted, corolla ± greened or leafy; bracts and calyx lobes rolled inwards. A. officinalis: Anthocoptes aspidophorus

6a Flower buds swollen, unopened. Containing many mites. A. officinalis: Unidentified gall mite

6b Similar malformation caused by gall midges. A. officinalis: Unidentified gall midge

1a On parts above ground => 4

1b On roots or root collar => 2

2a On roots => 3

2b Root collar with rotund succulent, one-chambered swelling, up to 8 mm long. Contains a single larva. A. alyssoides: Ceutorhynchus assimilis

3a Galls ± rotund, up to 5 mm long, succulent, many on side roots. A. montanum: Meloidogyne hapla

3b Main- and side roots with conspicuous, spindle- to barrel- shaped, succulent swellings. Inside many cell masses with minute spores. Alyssum spp.: Plasmodiophora brassicae

4a Malformations with white pads caused by fungi => 10

4b Malformations caused by animals => 5

5a On inflorescences or flowers => 9

5b On vegetative parts => 6

6a Stem with localised swellings. Galls with midge larvae inside or containing causers in rimmed depressions => 7

6b Young shoots ± stunted and arched; leaves clustered; often nest-like deflected; close to the froth-covered nymph ± deep green discoloured. Alyssum spp.: Philaenus spumarius

7a Larvae are inside gall => 8

7b Stem bulging over variable length, variously distorted, outside with single or several rimmed depressions containing a scale insect. Alyssum spp.: Planchonia arabidis

8a Terminal part of stem stunted, transformed into a 10‒15 mm long, 6–8 mm wide gall. Leaves densely clustered, swollen at base. A. alyssoides, gmelinii, murale: Janetiella fallax

8b Shoot with up to 4 mm long, about pea-size, spindle-shaped swellings. A large chamber contains several red larvae. A. alyssoides, montanum: Dasineura alyssi

9a Inflorescence disfigured over a substantial part. Flowers greened and/or leafy; abnormally white pubescent. A. alyssoides, hirsutum, Ptilotrichum halimifolium, tortuosum: Aceria drabae

9b Flowers swollen, unopened. Containing a single larva. Aurinia saxatilis: Unidentified gall midge

= The gall midge Dasineura auriniae is described from swollen flower buds of Aurinia petraea.

10a Rotund to oval, several mm long, at first closed, glossy, porcelain-like ± swollen bulges on stems and leaves. Later on with mealy dusting of closely arranged conidiophores. Alyssum spp.: Albugo candida

10b Leaves often distorted, usually with several, solitary or clustered, little wart- to bulge-like swellings on upper side, more rarely on underside. In the cavities branched conidiophores make narrow erinea. Sometimes expanded covers on bulging midribs or variously disfigured flowering or non-flowering shoots. Alyssoides utriculata; Aurinia saxatilis: Hyaloperonospora galligena

1a On above-ground parts => 4

1b On roots or root collars => 2

2a On main- or side roots => 3

2b Root collar with rotund succulent, one-chambered swelling, up to 8 mm long. Contains a single larva: Ceutorhynchus assimilis

3a Main- and side roots with conspicuous, spindle- to barrel- shaped succulent swellings. Many cell masses inside with minute spores: Plasmodiophora brassicae

3b Spindle-shaped or nodular swellings of side roots, up to 5 mm long: Meloidogyne hapla

4a Malformations at surface with fungus sori => 10

4b Malformations without fungal sori => 5

5a Malformations on shoot tips or on leaf blades => 7

5b Galls on shoots or petioles => 6

6a Stems or petioles, rarely leaf veins, with spindle-shaped, 10–20 (25) mm long, at first also internal deep green swellings. Containing a single larva: Ceutorhynchus chalybaeus

6b Stem with bulges of variable size, later on blackish; containing many oospores inside the tissue: Hyaloperonospora niessliana

7a Galls caused by aphids or spittlebugs => 8

7b Mite gall. Shoot with irregular development of disfigured leaves. Inducer unidentified – ? gall mite

8a Malformations caused by aphids => 9

8b Malformations caused by spittlebugs. Leaf blade often strongly deflected, at margin ± bent inwards. Leaf blade, especially between the veins, ± bulging; deep green close to the froth-covered nymph: Philaenus spumarius

9a Vegetative and flowering shoot tips clustered, usually with several disfigured together. Leaf blades ± deflected, curled. Flower parts disfigured, ± greened. Fruits sometimes distorted and thickened: Lipaphis alliariae

9b Malformation inconspicuous, usually restricted to single or several terminal leaves: Myzus persicae

10a Sori of fungus expanded, loose covers, consisting of branched conidiophores: Hyaloperonospora niessliana

10b Conidiophores not branched, united into dense, at first glossy, porcelain-like, sometimes bulging swollen sori which release mealy dusting of spores after rupturing: Albugo candida

1a Leaves remarkably long stalked, more erect, their leaf blades smaller, ± pale green, with orange-yellow to -red, often crowded fungal sori on the underside => 8

1b Malformations on leaf blades or -stalks without conspicuously coloured sori => 2

2a Malformations on leaf blades caused by aphids or spittlebugs => 7

2b Other causes => 3

3a On leaf blades => 4

3b Petiole thickened. A. vulgaris: Planchonia arabidis

4a Leaf blade folded, twisted, or with minor bulge-like swellings => 5

4b Leaf blade crumpled. Infestation sites sometimes conspicuously yellowish to reddish. With single or gregarious froth-covered nymphs on underside with black margined and castellated scale surrounded by a white margin of wax. A. alpina, glabra, pratensis, vulgaris: Bactericera femoralis

5a Leaf blade folded or twisted => 6

5b Leaf blade with slightly bulge-like, ± discoloured swellings, depressions on the underside of whitish covers of sori with branched conidiophores. Alchemilla spp.: Peronospora alchemillae

6a Leaf blade irregularly folded, here and there on underside with flat, rotund depressions, not abnormally pubescent. A. vulgaris: Unidentified gall mite

6b Leaf blade variously twisted, yellowish spotted. A. fissa: Unidentified gall mite

6c Minor swellings on ± stunted leaves. A. glomerulans, murbeckiana, xanthochlora: Calepitrimerus alchemillae

7a Leaf blade acutely bent downwards over large part; crumpled and dark green close to the froth-covered nymph. Alchemilla spp.: Philaenus spumarius

7b Leaf blade strongly curled; colonies of aphids on undersides. Alchemilla spp.: Aulacorthum solani

8a Underside often completely occupied with rotund or oblong, soon coalescing, orange-yellow to red lead sporangia. Alchemilla spp.: Trachyspora alchemillae

8b Similar malformations on A. alpigena, alpina, hoppeana, indivisa, nitida, velebitica: Trachyspora melospora

8c Very close to this fungus is a species occurring with expanded mycelium on hypertrophied chlorotic shoots of A. pentaphylla, with similar biology: Trachyspora pentaphylleae

1a On parts above ground => 3

1b On roots or on root collar => 2

2a Roots with expanded spindle- to barrel-shaped succulent swellings, ± bulging. “Clubroot”. R. austriaca, islandica, sylvestris: Plasmodiophora brassicae

2b Globular, pea- to cherry sized succulent galls on root collar, occasionally clustered. R. amphibia, islandica: Ceutorhynchus assimilis

3a On shoot tips, leaves, inflorescences or flowers => 6

3b Galls mainly or only on shoot axis => 4

4a Galls expanded, of very variable shape => 5

4b Axis with spindle-shaped, 10–15 (30) mm long, usually deep green swelling. Containing a single larva. R. amphibia: Ceutorhynchus chalybaeus

5a Youngest shoot parts swollen over ± extended length, soon covered with a loose, white down of branched conidiophores. R. amphibia, austriaca, islandica, palustris, sylvestris: Hyaloperonospora rorippae-islandicae

5b Young parts of non-flowering or flowering shoots with elongate bulges, at first glossy-white porcelain-like, later on with mealy dusting, sometimes coalescing into larger clusters, also curved swellings. Rorippa spp.: Albugo candida

6a On leaves, inflorescences or flowers => 8

6b On the tip of shoots, developing leaves or inflorescences => 7

7a Tip of main- and side shoots, also axial buds transformed into spongy, whitish, coalescing masses; the neighbouring, partially normally developed organs densely clustered, basal parts of petioles or flower buds variously swollen close to the gall. Sometimes the inflorescence galls are overtopped by some atrophied flowers. Containing several yellow- to orange-coloured larvae. R. amphibia, x anceps, austriaca, palustris, pyrenacia, sylvestris & subsp. kerneri: Dasineura sisymbrii

7b Longitudinal growth of axis stunted. Leaves or all parts of infected inflorescence clustered. All parts at base ± succulent, but not swollen and spongy, gall very variable. Containing several whitish- to lemon yellow, jumping larvae. R. palustris, pyrenaica, sylvestris: Contarinia nasturtii

8a On inflorescences or flowers => 13

8b On leaves => 9

9a Galls caused by animals => 12

9b Galls caused by fungi => 10

10a Sori white => 11

10b Leaves, also stem, with rotund, dull brown to black warts, or petioles with oblong, up to 1.5 mm long, bulge-like swellings; organs if strongly infected ± curved. R. amphibia: Physoderma vagans

10c On the same host the very similar punctiform, rotund, nodular protruding swellings on leaf blades or in flat brown bulges on petioles are attributed to Physoderma magnusianum

10d Small hard gregarious pustules, less than 0.5 mm across. Rorippa spp.: Synchytrium aureum

11a Leaf midrib, also stalks and venation, with spindle-shaped bulges. Leaf blade with ± rotund, pale green swellings. Sori at first closed, white and glossy, porcelain-like, then with dusting. Rorippa spp.: Albugo candida

11b Largely similar malformations, covered with loose down of conidiophores. R. amphibia, austriaca, islandica, palustris, sylvestris: Hyaloperonospora rorippae-islandicae

12a Basal leaves stunted. Midrib shortened, leaf blade ± nested, dark green, bent or rolled upwards. Strongly infected plants do not flower. R. amphibia: Aphis triglochinis

12b Leaves deflected over their top. Variously distorted and ± curled; sometimes the axis is stunted on one side and bearing several clustered disfigured leaves Rorippa spp.: Philaenus spumarius

13a Galls restricted to flowers => 15

13b Malformations on other parts of inflorescence => 14

14a Upper leaves disfigured. R. austriaca: Unidentified gall mite

14b Axis stunted. Flowers clustered, aborted. R. sylvestris: Aphis gossypii and/or Aphis nasturtii

15a Flowers unopened, often reddish discoloured on the outside, ± spongy thickened; stalk sometimes slightly elongated, resulting in a deflected gall. R. x anceps: Unidentified gall midge

15b Flowers swollen, ± egg-shaped, unopened. Corolla absent. Stamens short, thickened; ovary thickened. Containing several whitish- to pale yellow jumping larvae. R. palustris, pyrenaica, sylvestris: Contarinia nasturtii

1a Malformations on inflorescences or their parts, or fruit galls => 7

1b Malformations on leaves or stems => 2

2a Leaves with expanded malformations => 4

2b Vitreous bulges or pads bearing fruiting bodies on leaves, -stalks, or on stems => 3

3a Spindle-shaped, vitreous bulges on basal stem part, on petioles, midrib and leaf veins. T. japonica: Protomyces macrosporus

3b Bulges yellowish, soon bearing aecia, on the axis of leaves, also on younger stem parts. T. arvensis & subsp. neglecta, japonica, nodosa: Uromyces lineolatus

3c T. japonica has furthermore been indicated as host for Puccinia chaerophylli

4a Malformations caused by aphids or spittlebugs => 5

4b Tip of leaflets variously rolled or strongly curled. T. arvensis, japonica: Aceria peucedani

5a Malformations caused by aphids => 6

5b Main- and side midrib, together with ± curled leaflets, strongly deflected; usually with several similarly disfigured leaves changed into a nest-like cluster. T. arvensis, japonica: Philaenus spumarius

6a ip of leaflet at first with small, upwardly open folds; causer also in ± swollen leaf sheaths. The side shoots that develop later in these sheaths curled; the umbels ± greened and/or leafy. T. arvensis, japonica: Hyadaphis foeniculi

6b Leaflets densely clustered on ± shortened midrib, disfigured; leaf blades irregularly deflected, twisted, curled and ± bulging. T. arvensis, japonica: Semiaphis anthrisci

7a Extensive malformations on inflorescences => 9

7b Localised galls on fruits or stalks of inflorescences => 8

8a Centre of umbel or stalk of umbel ± swollen, club-shaped. Inner wall, rough, covered with mycelium. Containing a single red larva. T. japonica: Lasioptera carophila

8b Fruit inflated, bladder-like; ± globular or flattened on one side, oblong-oval. Gall thin-walled sometimes reddened, protruding above the umbel. Containing 1 (–3) orange-red larvae. T. japonica: Kiefferia pericarpiicola

9a (Partial) umbels severely stunted; ± ball-like clustered; aphid galls => 10

9b Flowers in umbel clustered with umbel stalk often little stunted, variously leafy or only partially greened. T. arvensis, japonica: Aceria peucedani

10a Stalks of umbels and flowers often variously stunted, resulting in irregularly stunted parts. Flower bud disfigured, often mostly greened or even leafy. T. arvensis, japonica: Semiaphis anthrisci

10b Similar malformations. T. japonica: Cavariella pastinacae

1a On inflorescences, flowers and fruits => 10

1b On vegetative organs => 2

2a Localised or extensive malformations mainly on leaves or terminally on higher placed parts of shoot => 5

2b Galls on lower or middle stem parts => 3

3a The causers develop inside the galls => 4

3b Stem with bulging swellings of different length, mainly close to ground, bearing on their surface several rimmed depressions containing a nymph. Scrophularia spp.: Planchonia arabidis

4a Young shoots close to ground, or also on higher placed parts of side shoots, completely or locally severely stunted, spongy, often conspicuously curved with wrinkled surface. Occasionally encroaching onto petioles and basal parts of ± disfigured leaf blades. S. nodosa: Ditylenchus dipsaci

4b Stem with localised nodular or spindle-shaped, variously distorted swelling. Gall wall browned inside. Leaves clustered at infestation; complete plant ± disfigured. S. nodosa: Cause unknown – ? insect

5a Wart-shaped galls or expanded, variable malformations caused by fungi => 8

5b Malformations caused by animals => 6

6a Single or many leaves with bladder-like swellings or curls => 7

6b Leaves clustered, rosette-like; leaf blades thickened. S. umbrosa: Unidentified gall midge

7a Leaves stunted, with bulging reddened swellings. S. nodosa: Unidentified ? thrips

7b Leaf blade curled, strongly bent downwards at infestation, there deep green. Internodes ± stunted if infected, resulting in clustered ± curled leaves. S. umbrosa, nodosa: Philaenus spumarius

8a Malformations of undefined extent => 9

8b Galls wart-shaped, multi-cellular, less than 1 mm across, ± golden-yellow. Usually many on underside of basal leaves; also on petioles and young stems; sometimes joined into crusts or ridges. S. nodosa, umbrosa: Synchytrium aureum

9a Leaf blades on hardly swollen, rotund to widely expanded spots with usually yellow or reddish bordered sori of fungus. On main veins, petioles and stems developing sori more strongly thickened; bulges of variable size; diseased leaves and stems often severely distorted. At first with spermogonia and aecia, soon also bearing telia. Scrophularia spp.: Uromyces scrophulariae

9b Completely diseased young shoots at first develop faster and firmer than healthy ones, remaining lanky and bear pale-green leaves with narrowed, slightly thickened leaf blades, which are soon covered with a down of branched conidiophores on underside. S. nodosa, scopolii, umbrosa: Peronospora sordida

10a Flower or inflorescence galls => 11

10b Fruit slightly swollen and disfigured only if infected in right phase. Usually containing a single larva. Scrophularia spp.: Rhinusa tetra

11a Flower galls => 12

11b Inflorescence curved; terminal leaves curled. Flower buds contain several at first white, later on orange coloured larvae. S. nodosa, scorodonia: Macrolabis scrophulariae

12a Flowers strongly swollen, unopened. Calyx slightly changed; corolla thickened, especially the tube; stamens with thickened filaments transformed into irregular, leaf-like organs. Ovaries swollen; inner wall covered with dirty white mycelium. Containing a single yolk-yellow larva. S. canina, decipiens, grossheimii, nodosa, umbrosa: Asphondylia scrophulariae

12b Flowers swollen, globular, usually unopened. Stamens and pistil enlarged. Larvae live between flower parts, white to lemon-yellow, jumping. S. auriculata, canina, nodosa, schousboei, umbrosa: Contarinia scrophulariae

1a On above-ground parts => 4

1b On roots or root collar => 2

2a Considerable galls on root collar => 3

2b Roots with elongated spindle-shaped swellings, up to 5 mm long, bearing some lateral roots. Coalescing in rows in cases of heavy infestation. S. hispanica: Meloidogyne hapla

2c Lateral roots terminally thickened, ± curved, longitudinal growth stunted, prematurely shrivelled. Whole plant becoming stunted. S. hispanica: Paralongidorus maximus

3a Uniformly succulent, up to walnut size, ± rotund-ovoid proliferation on root collar, sometimes on root- and stem parts close to the surface. “Crown gall disease”. S. hispanica: Agrobacterium tumefaciens

3b Almost globular, glabrous, one-chambered swellings on root collar. Often several variously coalesced, depending upon the number of galls, to form crook-backed structures. One larva per chamber. S. humilis: Aulacidea hieracii

4a On capitula or flowers => 13

4b On stems or leaves => 5

5a Malformations on leaves => 6

5b Stems with conspicuous, crooked swellings at the surface mostly on all sides, 40–60 mm long, about 10 mm thick. Inside the stem are many, clustered rotund galls, each about 2 mm long, and each with one larva. S. austriaca, hispanica, humilis; Podospermum purpureum: Aulacidea scorzonerae

6a On leaf blades or leaf veins => 7

6b Leaf sheaths ± bladder-like swollen and discoloured. Enclosed shoot stunted, with severely stunted development. S. hispanica: cf. Brachycaudus tragopogonis

7a Malformations caused by superficial sori => 11

7b Galls with living animal inducers inside => 8

8a Galls predominantly on the leaf blade or on the secondary veins => 9

8b Midrib on the underside often with several galls, in loose or more clustered constellations appearing pale green, rotund-ovoid, 2–3 mm long, one-chambered. Containing a single larva. S. austriaca, hispanica, humilis; Podospermum purpureum: Aulacidea scorzonerae

9a Galls of definite shape; surface glabrous, usually ± reddened. Midge galls => 10

9b Flat, pale green, ± spongy, rugose galls, especially swollen at the veins and extending over at least 15 mm in length on the leaf blade, ± curved as result of the infestation. S. hispanica: Ditylenchus dipsaci

10a Leaf blade with round pustules, several millimetres wide; bulging on the upperside, yellowish or dirty crimson-red, sometimes surrounded by a reddish discoloured area; the underside lighter, flat. A pale orange-yellow larva. S. austriaca, humilis: Cystiphora scorzonerae

10b Elevated, elongated to spindle-shaped galls, up to 5 mm long, protruding from both leaf surfaces, often yellow or reddish bordered. Often many per leaf blade, the longitudinal stem predominantly situated in a secondary vein and extending on both sides on the leaf blade. Containing a single larva. S. humilis: Unidentified gall midge

11a Malformations with sori of true rust fungi (Uredinales) => 12

11b Oomycetes. Sori oblong-oval, initially closed and porcelain-glossy, white, opening later and with mealy dusting. S. austriaca, hispanica, humilis, parviflora; Podospermum canum, laciniatum; Scorzoneroides autumnalis, helvetica: Pustula obtusata

11c Oomycetes; upperside of the leaves with yellow or brown spots; on the underside a greyish brown fungal down consisting of erect, distally several times branched conidiophores; the final branches ending in an ovoid conidium. S. hispanica, humilis: Novotelnova scorzonerae

12a The primary uredomycelium usually pervades the whole host, whose parts are paler, more lanky or deformed in another way. Spores brown. Podospermum purpureum, roseum; S. austriaca, hirsuta, hispanica, humilis, mollis, papposa: Puccinia scorzonerae

12b Shoot etiolated by the expanded aecial mycelium. Leaves in case of heavy, infection, usually one-sided, conspicuously curved or even twisted. Aecia cup-shaped, later opening with frayed border, widely dispersed over leaves, stems and involucres; yellowish. S. austriaca, hispanica, humilis; Podospermum purpureum, roseum: Puccinia jackyana

13a Malformations induced by insects => 14

13b Diseased capitula already stunted early in development, shortened, initially turgid. Flowers soon completely destroyed and replaced by a black-violet, sparsely dusting spore mass. Podospermum canum, puurpurum, roseum; S. aristata, calyculata, hispanica, humilis, mollis: Microbotryum scorzonerae

14a Receptacle of the unopened flower head ± egg-shaped, swollen. In case of one-sided infestation ± curved. Usually containing one larva. Podospermum purpureum; S. parviflora; Scorzoneroides autumnalis: Trupanea stellata

14b Capitula conspicuously swollen, rotund to elongated ovoid. Galls in the shortened and broadened fruits. Wall thick and woody. Pappus shortened, with withered corolla mounted on the gall. Often many galls per flower head. One yellowish-white larva per gall. Podospermum purpureum, roseum; Scorzonera humilis, parviflora: Aulacidea abdominalis

14c Base of flower head is usually enlarged; the conglomerate of galls lignified, hard. Larval chamber is round or slightly ovate, developing in seeds which are slightly swollen. Pdospermum purpureum, roseum; Scorzonera humilis, parviflora: Aulacidea abdominalis

14d A stem swelling-like gall, usually located under the flower head, sometimes in the lower part of the stem; spindle-like or cylindrical stem enlargement, 30‒60 mm long, 10 mm in diameter; the surface with longitudinal ribs, as on the stem, sometimes the ribs are waved and distance between them is larger, depending on the diameter of the gall. In a longitudinal dissection, single 2 mm long larval cells are visible which are located near one another. The number of larval cells is larger towards the periphery of the gall. The stem above the gall is shortened and the flower head terminates its development. S. austriaca, hispanica, humilis; Podospermum purpureum: Aulacidea scorzonerae

14e Galls induced in achenes. Podospermum laciniatum: Aulacidea laurae

1a On axial parts of shoots, shoot tips, swollen buds or leaves => 2

1b Flowers disfigured; calyx swollen; corolla, stamens and ovaries aborted. Clinopodium acinos, Micromeria graeca, Clinopodium vulgare: Unidentified gall mite

1c Flowers disfigured. Micromeria graeca: Aceria saturejae

1d Calyx inflated, flower disfigured or aborted. Micromeria graeca subsp. fruticulosa: Asphondylia sp.

2a Malformation of many leaves on shoot tips, terminally on shoots or single leaves => 6

2b Galls on axial parts of shoots, sometimes encroaching onto leaves => 3

3a Swollen buds contain solitary gall midge larvae. Clinopodium alpinum, nepeta subsp. glandulosum. Asphondylia calaminthae

3b Shoot axis and underside of leaves long-haired white-erineum. Inflorescence stunted, especially along venation. Clinopodium vulgare: Unidentified gall mite

4a Causers occur inside galls => 5

4b Stem ± spindle-shaped or bulging, with several rimmed, irregular depressions containing the inducer. Clinopodium acinos: Planchonia arabidis

5a Stem with rotund to acuminated, egg-shaped swelling, up to 5 mm long, tough- and smooth-walled. Containing a single lemon-yellow larva. Clinopodium acinos, vulgare: Squamapion vicinum

5b Complete plant stunted. Stem distinctly shortened, spongy, swollen. Side shoots of more developed plants and basal leaf parts similarly disfigured to varied extent. Satureja hortensis: Ditylenchus dipsaci

6a Malformation of many leaves on shoot tips or terminally on shoots => 8

6b Localised galls on leaves, sometimes on basal young shoots => 7

7a Galls less than 1 mm across, multi-cellular, wart-shaped, ± golden-yellow; usually many on leaf underside, sometimes on petioles. Clinopodium vulgare: Synchytrium aureum

7b Leaf blades with yellowish rotund pads, several mm long, on leaf underside; their surface bearing aecia. Similar, more spindle-shaped bulges on leaf veins and -stalks as well as on shortened basal parts of shoot axis, sometimes strongly swollen and distorted. Clinopodium spp.; Micromeria hyssopifolia, varia; Satureja hortensis, thymbra: Puccinia menthae

7c Lower leaves turn brown and wither. On the underside a purple fungal down, consisting of vertical conidiophores that apically several times are dichotomously branching, each branch ending in a globular conidium. S. hortensis: Peronospora saturejae-hortensis

8a Curling of leaves caused by aphids or spittlebugs => 9

8b Leaves and generative primordia on shoot tip severely stunted, accumulated, tuft-like; ± disfigured and densely white pubescent. Clinopodium acinos, vulgare: Unidentified gall mite

9a Malformations caused by aphids => 10

9b Some internodes of stem shortened, sometimes ± bent. Leaves ± clustered, with several deflected over their tips, ± distorted, converging, nest-like, containing a froth-covered nymph. S. hortensis, montana: Philaenus spumarius

10a Terminal part of shoot axis ± shortened; side shoots variously stunted. Leaves ± clustered, curled, ± rolled inwards and downwards. Clinopodium acinos, grandiflorum, menthifolium, nepeta incl. subsp. glandulosum, vulgare: Aphis calaminthae

10b Leaf blade curled. Clinopodium acinos, menthifolium, vulgare: Aphis clinopodii

10c Similar malformations on Clinopodium vulgare: Aphis nepetae

10d Similar malformations on Satureja hortensis: Unidentified aphid

10e eaf blade swollen. Aphid green or yellow. Clinopodium alpinum, nepeta subsp. glandulosum: Aphis origani

1a On plant parts situated higher above-ground => 4

1b On roots, root collars or basal stem parts => 2

2a Galls on root collar or on neighbouring stem parts => 3

2b Roots with bulging, chambered swellings. Each chamber containing one larva. T. porrifolius: Aulacidea hieracii

= On T. porrifolius the eelworm Meloidogyne hapla has been recorded

2c Swelling on roots of T. porrifolius, pratensis: Orellia falcata

3a Root collar or basal stem parts with one-chambered, rotund, sometimes isolated, one-sided, succulent tough-walled swellings, or galls often in groups or rows coalesced into ± bumpy tubercles or even into several cm long, irregular bulges. In each rotund- oblong-oval 1–1.5 mm long larval chamber is one whitish larva. T. dubius & subsp. major, porrifolius, pratensis & subsp. orientalis: Aulacidea tragopogonis

3b Conspicuous, 2.5–3.5 x 4–5 cm large, rotund to oblong-oval, succulent proliferations on root collar, undulate on the surface. T. porrifolius: Agrobacterium tumefaciens

4a On capitula, florets or achenes => 10

4b Localised or elongate malformations on leaves or shoots, sometimes extending into the green parts of the inflorescence => 5

5a Malformations with sporulating fungal sori on the surface => 9

5b Malformations caused by animal inducers => 6

6a Malformations predominantly developing on leaves => 7

6b On the base of the main stem, one-sided brown-yellowish multi-chambered swelling. T. dubius & subsp. major, porrifolius, pratensis & subsp. orientalis: Aulacidea tragopogonis

7a Inducers inside the galls => 8

7b Leaves sometimes ± twisted, curled; also the sheaths abnormally inflated. T. crocifolius, dubius, porrifolius, pratensis & subsp. orientalis: Brachycaudus tragopogonis

7c Malformations have been recorded caused by froth-covered nymphs. T. orientalis: Philaenus spumarius

8a Leaf blade with several slight swellings, separated from each other and therefore inconspicuous, about 1 x 2 mm long, situated between the veins. Each containing a larva. T. pratensis: Unidentified gall midge

8b Basal leaves with petioles and basal leaf blades distinctly shortened, pale green, in ± expanded areas swollen, spongy-undulate; other parts of leaf blade ± stunted. T. pratensis: Ditylenchus dipsaci

9a Shoots over large parts ± disfigured and etiolated, often remaining sterile. Leaves narrowed, ± shortened, pale green; like the stem occupied with many distantly, honey-yellow spermogonia and white margined, orange-red aecia. Infestation also occasionally extending into similarly deformed involucres and even into achenes. Tragopogon spp.: Puccinia hysterium

9b Similar malformations on T. dubius, porrifolius, pratensis & subsp. orientalis: Puccinia brachycyclica

9c Oblong-oval sori, initially closed and porcelain-glossy, later breaking open and with mealy dusting, occur rather often on all green parts and induce excessive branching and other malformations on early affected developing buds. Tragopogon spp.: Pustula obtusata

10a Malformations on capitula => 12

10b Galls on single or several florets, especially on achenes of capitula that look normal from the outside => 11

11a Basal part of the achene transformed into a mustard seed-like gall, large, thin- and hard-walled, one-chambered. Containing a single larva. T. pratensis: Unidentified gall wasp

11b chene spindle-shaped, swollen. T. pratensis: Unidentified gall midge

12a Capitula greened or disfigured by fungi which later produce dusting of spores => 15

12b Malformations caused by animal inducers => 13

13a Malformations caused by fly maggots or midge larvae => 14

13b Capitula remaining closed. Florets ± atrophied, embedded by a bladder-like malformation, swollen, conspicuously cornicular converging, one-sided enclosed by involucral bracts. T. pratensis: Cause unknown – cf. Brachycaudus tragopogonis

14a Capitula remaining closed; slightly swollen at base, variously disfigured and curved. Containing several whitish to yellow jumping larvae. T. dubius, pratensis: Contarinia tragopogonis

14b Hardly conspicuous, often one-sided malformation of the flower head caused by single larvae, usually living between the achenes. T. pratensis: Ensina sonchi

15a Developing capitula shortened, ± globular to broad oval, swollen. Flower parts soon to a large extent affected by blackish-dark violet discolouration, later with dusting of spore masses. Tragopogon spp.: Microbotryum tragopogonis-pratensis

15b Malformation and ± greening of all florets in a flower head. T. pratensis subsp. orientalis: Cause unknown – ? gall mite

1a On inflorescences, bearing flowers or fruits => 6

1b On vegetative organs => 2

2a On axial parts of shoots => 5

2b On leaves => 3

3a Malformations on leaf blade or spindle-shaped swellings on stems => 4

3b Wart-shaped many-celled galls, less than 1 mm long, on leaf blades, more rarely on petioles. P. hemisphaericum: Synchytrium vulgatum

4a More or less expanded malformations on leaves, occasionally also on stems, caused by only telia developing rust fungi. Leaves of usually systemically infected plants grow more erect and develop faster; they exhibit an abnormal shape of leaf blades, are longer stalked than healthy ones and large parts of underside are covered with rather densely arranged dark-brown telia. Phyteuma spp.: Uromyces phyteumatum

4b Rather loosely arranged aecia on leaf underside of large parts of sometimes long stalked, etiolated leaf blades; exceptionally also densely arranged on longer, slightly spindle-shaped swellings of leaf veins, -stalks and stems. Phyteuma spp.: Puccinella caricis-sempervirentis

5a Shoot axis with successive lobular constricted swellings on twigs. P. spicatum: ? gall midge, pteromalid wasp

5b Shoot axis in the middle or in upper part swollen like rope of pearls. Gall chambers alternating, each containing a single larva. P. orbiculare: ? gall midge, gall wasp

6a Malformations mainly of flowers or their parts => 7

6b Inflorescence shortened and thickened. P. spicatum: Unidentified lepidopteran

7a Flowers or their ovaries strongly swollen => 8

7b Flowers disfigured, their parts variously greened or leafy. P. limonifolium: Aculus schmardae

7c lowers abnormally hairy, greened, leafy. Asyneuma [= Podanthum] canescens, limonifolium: Aculus podanthi

8a Corolla strongly swollen, bladder-like, unopened, inside at base with involute hairs, with several orange-coloured larvae in between. Often on several flowers of an inflorescence. Phyteuma spp.: Dasineura phyteumatis

8b Strongly swollen ovaries associated with other malformations usually on many flowers in a spike. Phyteuma spp.: Miarus campanulae

1a On above-ground parts => 3

1b On root and root collar => 2

2a Roots with spindle-shaped to slightly nodular swellings, bearing isolated lateral roots. T. officinale: Meloidogyne hapla

2b Considerable tuft-like proliferations on root collar. T. officinale:
Agrobacterium tumefaciens

3a On inflorescences or capitula => 16

3b On leaves => 4

4a Exclusively or predominantly on petiole, midrib and main veins => 12

4b Extensive malformation, or localised galls on leaf blade => 5

5a Galls local, sometimes clustering into larger groups => 8

5b Leaf blade with extensive malformations of irregular composition => 6

6a Malformations caused by aphids or cercopids => 7

6b Leaf blade ± shrivelled, converging, curled, twisted or rolled upwards, roll may be haired; leaflets narrowed, margin sometimes lacerate. T. officinale: Aculus rigidus

6c Curled leaves, contain froth-covered nymphs. T. officinale: Philaenus spumarius

7a Leaf blades sometimes spirally twisted; contain dark brown aphids. T. officinale: Uroleucon taraxaci

7b Leaf blade curled, with bladder-like swellings. Aphid green. T. officinale: Aulacorthum solani

7c Little indentation of the leaf blade. T. officinale, palustre: Trioza dispar

8a Single galls more than 4 mm long => 11

8b Single galls smaller => 9