Plant Parasites of Europe

leafminers, galls and fungi

gallers on Symphytum

Dichotomous table for gallers on Syphytum

by Hans Roskam

1a On flowers or fruits => 9

1b On leaves, sometimes on stems => 2

2a Malformations caused by animals living on surface of host => 7

2b Malformations caused by fungi, fruiting inside or on surface of host => 3

3a Malformations conspicuous, bearing yellowish sori => 6

3b Galls small, up to 1.5 mm across. Spores originate inside nutritive cells => 4

4a Galls on leaf blades => 5

4b Galls only on hairs of leaves and stem. Hairs distinctly shortened and swollen, often with short, immediately narrowed, acutely bent tip. Inside are single or several rotund summer- or perennial sporangia up to about 50 µm large. S. officinale: Synchytrium trichophilum

5a Leaves with several wart-shaped protruding, small, multi-cellular galls, which develop in a centrally situated strongly enlarged nutritive cell yellow perennial sori. S. officinale: Synchytrium jaapianum

5b Expanded parts of leaf blade with many, densely arranged, but usually solitary, rotund to oblong-oval reddish- to dark brown, flat bulges. S. officinale: Physoderma speciosum

6a Tubercular bulges rotund on underside of leaf blade, on main veins, petioles and stems oblong-oval spindle-shaped, up to 15 (25) mm long, orange-coloured ± reticulate. Symphytum spp.: Puccinia recondita

6b Diseased plants or leaves lanky, paler. Large parts of leaf blade bearing small reddish- to brownish-yellow uredinia on underside. Symphytum spp.: Melampsorella symphyti

7a Malformations caused by aphids, spittlebugs or thrips => 8

7b Leaf blade curled, yellowish discoloured. Many white larvae on underside. S. asperum, officinale: Dasineura foliumcrispans

8a Leaf blade arched deflected, ± converging and curled. Symphytum spp.: Philaenus spumarius

8b Leaf blade rolled upwards, ± bent, sickle-shaped. S. cordatum, officinale: Aphis symphyti

9a On inflorescences or fruits => 10

9b On fruits. Development of several mericarps stunted, the remainder enlarged and white pubescent. Corolla disfigured, only opened a little and remaining unopened. Fruit containing several white larvae. S. officinale: Unidentified gall midge

10a Malformations of single or several flowers without conspicuous stunting of inflorescence => 11

10b Malformation and stunting of inflorescence as well as neighbouring leaves. Flowers distorted and disfigured; leaves rolled and curled. S. officinale: Dictyla humuli

11a lowers unopened, variously greatly swollen, especially base discoloured. Calyx sometimes with white-felt-like pubescence. Corolla distorted. Stamens and ovaries shortened and thickened. Often many white to yellowish, non-jumping larvae inside flowers. S. asperum, officinale: Dasineura symphyti

11b Flowers unopened, only slightly swollen at base. Larvae jumping. S. officinale: Contarinia symphyti

11c Flowers strongly swollen, especially in basal part. Calyx often conspicuously enlarged; corolla thickened, ± greened. Receptacle and ovary strongly swollen; containing several white beetle larvae. S. officinale: Ceutorhynchus sp.

Last modified 14.iv.2020