Trisetum umbratile (Kitag.) Kitag.

This is a locally distributed variant of Trisetum sibiricum with small spikelets and almost straight awns.

Culms erect, slender, 70–90 cm tall, glabrous. Leaf sheaths equaling or shorter than internodes, glabrous, outer margin ciliate at mouth, margins closed near base; leaf blades linear, 8–30 cm, 2–7 mm wide, scabrid; ligule 1–2 mm. Panicle lax, broadly lanceolate in outline, up to 22 cm, green; branches capillary, smooth in lower part, upper part scabrid. Spikelets 4–5(–6) mm, florets 1 or 2; rachilla hairs ca. 1.4 mm; glumes unequal, lower glume oblong-lanceolate, 2.5–4 mm, upper glume oblong, 4–5 mm; lemmas 4.5–5.5 mm, scabrid-papillose, awned from above middle, apex 2-toothed, teeth ca. 1.5 mm, acute; awn up to 6.5 mm, straight or almost so, not twisted; palea keels indistinctly scaberulous. Anthers ca. 2 mm. Fl. and fr. Jul–Sep.

Marshy meadows and in forest. Heilongjiang, Jilin, Liaoning, Nei Mongol (Yakeshi) [Korea, Russia (Ussuri)].

Trisetum sibiricum Ruprecht var. umbratile Kitagawa, Rep. Inst. Sci. Res. Manchoukuo 4: 77. 1940; T. sibiricum subsp. umbratile (Kitagawa) Tzvelev.