Plant Parasites of Europe

leafminers, galls and fungi

gallers on Stipa

Dichotomous table for gallers on Stipa

(incl. Orthoraphium)

by Hans Roskam

1a On inflorescences, florets or fruits => 6

1b On leaves, stems or stalks of ± undeveloped panicles => 2

2a Several internodes of the initially elongate culm occupied by extensive patches of smut. Also on possible primordia of panicles; sometimes on leaves => 5

2b Malformations caused by animal parasites => 3

3a Culm with elongate spindle-shaped swellings => 4

3b Inner side of leaf sheaths covering parts of culm, or undeveloped stalks of panicles and occasionally even the glumes, often with long expanded rows or crusts of blister-like, at first white, then dark brown tuberculi. S. capillata: Steneotarsonemus graminis

3c In similar galls on S. capillata, pennata: Steneotarsonemus canestrinii

4a Culm above the 3th or 4th node with oblong, weak swelling. Pith containing a single larva. S. capillata: Tetramesa aciculata

4b Elongate spindle-shaped, weak swelling on culm of S. pennata. Containing a single larva. Tetramesa sp.

4c On S. capensis: Tetramesa stipae

5a Culms and possibly stalks of inflorescences with expanded blackish patches of smut on all sides. S. capillata, pennata: Sphacelotheca valesiaca

5b Similar infestation. Spores smaller, 4–6 x 3–5µ, reddish-brown, glabrous. S. capillata, dasyphylla, eriocaulis, pennata, pulcherrima: Tranzscheliella minima

6a Midrib of spikelets abnormally elongated, with swellings up to about 10 mm long, spindle-shaped, occasionally 2- or 3-winged, grain-like, sometimes ± curved. Containing a single larva. S. borysthenica, eriocaulis subsp. austriaca, pennata: Tetramesa scheppigi

6b Glumes and flower parts coalesced, transformed into a 7–10 mm long, elongate spindle-shaped, fruit-like gall. Containing a single larva. S. capillata, parviflora: Tetramesa cylindrica

6c Spikelet swollen, with lateral exit hole. S. capillata, parviflora: Tetramesa cylindrica

Last modified 24.v.2020