Plant Parasites of Europe

leafminers, galls and fungi

gallers on Anthoxanthum

Dichotomous table for gallers on Anthoxanthum

by Hans Roskam

1a On above-ground parts => 2

1b Roots with spindle-shaped, crooked or half screw-shaped bent swellings a few mm long. A. odoratum: Subanguina radicicola

2a On inflorescences or flowers => 6

2b On vegetative parts => 3

2c Whitish, at surface yellowish or brownish patches, which envelope a large area of the upper part of stem, of which further development is stunted. Node of stem rarely swollen, encircled by fungus stroma, yellowish when mature; several nodes may be affected; flowering stunted; stroma contains narrow asci and filamentous spores. A. odoratum: Epichloë typhina

2d At the base of stem, weak swelling containing one (or maybe sometimes several) white larva or flax seed like puparium. A. odoratum: Mayetiola sp.

3a Leaves with several parallel stripes caused by smuts => 5

3b Complete plant stunted in development => 4

4a Shoot at base slender onion-like swollen; plant more densely foliate. Stem not or only slightly developed. Leaves ± undulate and thickened; many eelworms inside. A. odoratum: Ditylenchus dipsaci

4b Complete plant stunted; inflorescence discoloured; contains a fly maggot. A. odoratum: Unidentified dipteran

5a Spores solitary, 8–12 µm across. Mass black. Stripes also occurring on stems and parts of spikes which remain closed for a longer time. A. odoratum: Ustilago striiformis

5b Spores in clusters of 2–5, enveloped by sterile auxiliary cells. Smut stripes occasionally also on leaf sheaths, stems and affected spikes. A. odoratum: Urocystis roivainenii

6a Inflorescence disfigured by animal parasites => 7

6b Ovary transformed into inconspicuous smut grains about 2 mm long, 1 mm wide. A. odoratum: Tilletia anthoxanthi

7a Axis of inflorescence wriggled; spikelets conglomerate. A. odoratum:
Unidentified tarsonemid mite

7b 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. A. odoratum: Aceria tenuis

Last modified 13.v.2020