Plant Parasites of Europe

leafminers, galls and fungi

gallers on Apera

Dichotomous table for gallers on Apera spica-venti

by Hans Roskam

1a Galls of various shape on panicles, flowers or fruits => 4

1b Galls on vegetative parts => 2

2a Localised galls on stems or leaves => 3

2b Young plants severely stunted. Shoots swollen, spongy especially at base; leaves reduced and bent. Ditylenchus dipsaci

3a Stem with weak, locally rimmed depressions below the slightly swollen sheath. Containing single orange-yellow larvae. Lasioptera calamagrostidis

3b Leaf blades at base usually with reddish to violet, slim bulging, swellings, 5–30 mm long. Anguina graminis

4a Malformations of ovaries => 5

4b Axial parts of panicles especially at base strongly wriggled, therefore appearing shortened; spikelets gathered together, usually remaining closed; flower parts and glumes not enlarged, sometimes greened. Unidentified eelworm

4c 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. Aceria tenuis

5a Ovaries swollen bottle-shaped, usually discoloured violet, glumes not enlarged. Anguina agrostis

= Sometimes the sac fungus Dilophospora alopecuri occurs in ovaries of many grasses when eelworms are associated

5b Ovaries temporarily swollen, soon transformed into rotund to oblong smut grains, in the pendant panicles. Fresh sori smelling. Plant hardly disfigured. Tilletia separata

Last modified 1.vi.2020