Avena clarkei Hook.f.
Tufted perennial; culms 20-70 cm high, erect or geniculately ascending, puberulous especially below the inflorescence. Leaf-blades 4-20 cm long, 1.5-2(-4) mm wide, flat, pubescent to scaberulous. Panicle lanceolate to subcylindrical, loose or sometimes ± dense, the axis and branches puberulous, 4.5-18 cm long, 1-3 cm wide. Spikelets 2-3-flowered, 5-8.5 mm long excluding the awns; glumes unequal, lanceolate, acute, the lower 3-nerved, 4-6 mm long, the upper (4.5-)5.5-7.5 mm long; lemma narrowly elliptic, (5.2-)5.5-7mm long; awn 4-8 mm long, strongly recurved.
Fl. & Fr. Per.: July-September.
Syntypes: Kashmir, Clarke 31514, 31517; Northwest India, Clarke 22985, 24605 (all K).
Distribution: Pakistan (N.W.F.P. & Kashmir); Nepal and Northwest India.
Trisetum clarkei and Trisetum spicatum can, at times, be very difficult to distinguish. Their obvious differences, clearly seen when good specimens are placed side by side, preclude the possibility that they are only subspecies or conspecific. There are no substantial quantitative differences except that in Trisetum clarkei the glumes and lemmas are slightly narrower than in Trisetum spicatum, a feature that correlates well with the looseness of the panicle. It is possible that the boundary between the two is obscured by hybridisation.
Trisetum clarkei is common in alpine pastures from 2700 to 4000 m.