Plant Parasites of Europe

leafminers, galls and fungi

gallers on Clematis

Dichotomous table for gallers on Clematis

by Hans Roskam

1a On above-ground parts => 2

1b Side roots with nodule-shaped swellings. Clematis spp.: Meloidogyne hapla

2a More or less expanded, usually bulging galls caused by smut fungi => 8

2b Malformations caused by animal parasites => 3

3a On leaves or flowers => 4

3b Young shoot axis, petiole, midrib and leaf veins with linearly arranged pustule-shaped swellings, about 3 mm long and 1 mm wide each containing a single egg (“procecidia”: oviposition scars, not true galls). C. flammula, integrifolia, orientalis, recta, vitalba: Eurhadinoceraea ventralis

3c Terminal stem gall consisting of a pair of small, densely haired leaves containing the shortened shoot. C. flammula: Dasineura sp.

4a Malformations with ± abnormal pubescence or flower galls => 6

4b Leaf blades not abnormally pubescent, rolled at margin => 5

5a Leaf margin narrowly rolled inwards. C. alpina: Phyllocoptes atragenes

5b Leaf blades upwardly rolled at tips of shoots. Roll on younger leaflets often occupying the whole leaf blade. C. vitalba, rarely on C. flammula: Aceria vitalbae

6a Galls on leaves, sometimes extending to inflorescence => 7

6b Globular leaf bud gall of vegetative tip, ± 7 mm across, consisting of several densely haired leaves among which rose-red larvae develop. C. flammula: Jaapiella clematidicola

6c Flower bud swollen, remaining closed. C. orientalis, recta, vitalba, viticella: Dasineura clematidina

7a Leaf blade with protuberances and abnormal pubescence. Inflorescence and flowers disfigured. C. recta: Unidentified gall mite

7b Leaf blade with marginal rolls or folds and thickening, especially along the midrib; partially also with protrusions as well as abnormal pubescence. C. alpina, cirrhosa, flammula, recta, vitalba: Phyllocoptes heterogaster

7c Similar, glabrous galls on C. flammula: Epitrimerus flammulae

7d Leaves of the undeveloped closed buds conspicuously whitish pubescent; also the ± developed leaves with similar pubescence occurring, mainly on the leaf veins and -stalks. C. recta: Dasineura sp.

8a Malformations caused by rust fungi fruiting on surface => 9

8b Often with associated arching, initially lead-grey translucent, after opening with black dusted bulges on leaves and young stems caused by smuts. C. alpina, sibirica: Urocystis mustaphae

9a Leaf blades, more rarely also the midrib and stalks, with ± conspicuous, rotund pads, or elongated brown bulges which remain closed for a long time and bear 2-celled telia. C. alpina: Puccinia atragenicola

9b Leaf blades, leaf veins, -midrib, -stalks or stems with conspicuous, often yellow-brown, ± fleshy swellings of various size; pads rotund on leaf blades, protruding on underside, bulging on stem parts, and often considerably arched; soon with spermogonia and cup-shaped opening aecia. This species, which has been recorded on many Clematis as “Aecidium clematidis, might be subdivided into several rust fungi, which are morphologically ± similar, but ± distinct in the spore stages: Puccinia recondita, P. alnetorum, P. hordei-maritimi, and P. clematidis-secalis

Last modified 8.iv.2020