Dichotomous table for gallers on Isopyrum thalictroides
(incl. Leptopyrum fumarioides.)
by Hans Roskam
1a Expanded galls caused by rust fungi which fruit on the outside => 2
1b Wart-shaped, pearl-like gall consisting of only a few cells on leaves and stems. Sporangia colourless, with a nutritive cell inside. Synchytrium anomalum
2a Swellings bearing yellow aecia => 3
2b Swellings and malformations, up to 1 cm long, on stems, petioles and leaf veins with fungus developing only black, normally 3-celled teliospores, with dusty sori. Triphragmiopsis isopyri
3a Aecia on Leptopyrum fumarioides:
a Aecia golden-yellow, usually on distinct bulges on underside of veins, midrib or stalk of leaves. Puccinia actaeae-elymi
b Galls similar. Aeciospores narrow fine-warty. Outer wall of peridium 6–7 μm thick, transversely striate; inner wall coarse warty, 2–3 μm thick. Fungus alternating to wheat and related grasses. Puccinia recondita
3b Thickened bulges on the leaf axis and leaf blade. Puccinia milii-effusi