Plant Parasites of Europe

leafminers, galls and fungi

gallers on Teucrium

Dichotomous table for gallers on Teucrium

by Hans Roskam

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

Last modified 2.v.2020