西伯利亚三毛草 xi bo li ya san mao cao

Trisetum flavescens (Linnaeus) P. Beauvois subsp. sibiri-cum (Ruprecht) T. Koyama; T. flavescens var. sibiricum (Ruprecht) Ohwi.

Perennial, loosely tufted, shortly rhizomatous. Culms solitary or few, 50–120 cm tall, 1.5–3 mm in diam., glabrous, 3–4-noded. Leaf sheaths mostly shorter than internodes, glabrous or lower shortly pubescent, margins joined near base; leaf blades broadly linear, 6–20 cm, 4–9 mm wide, glabrous or adaxial surface scattered pilose, ligule 1–2 mm. Panicle lax, narrowly oblong to lanceolate in outline, 10–20 cm, much branched, yellowish brown; branches 3–8 at lowest node, slightly scabrid, up to 6 cm. Spikelets 5–10 mm, florets 2–4; rachilla hairs ca. 1 mm; glumes unequal, lower glume 4–6 mm, upper glume 5–8 mm, apex acuminate; callus glabrous or with few very short hairs; lemmas 5–7 mm, firm, golden brown, finely but densely scabrid, awned from upper 1/3, apex 2-toothed, teeth triangular; awn 5–9 mm, strongly recurved, lower part straight or slightly twisted; palea 3/4 lemma length or longer, keels indistinctly scaberulous. Anthers 2–3 mm. Fl. and fr. Jun–Aug.

Grassy mountain slopes, open forest, marshy places among shrubs; 700–4200 m. Gansu, Hebei, Heilongjiang, Henan, Hubei (Shennongjia), Jilin, Liaoning, Nei Mongol, Ningxia, Qinghai, Shaanxi, Shanxi, Sichuan, Xinjiang, Xizang [Japan, Kazakhstan, Korea, Mongolia, Russia; SW Asia (Caucasus), E Europe, North America (Alaska)].

This species is a good forage grass, closely related to Trisetum flavescens (Linnaeus) P. Beauvois from Europe. Trisetum flavescens has been introduced into many temperate countries for forage. It can be distinguished from T. sibiricum by its pilose lower leaf sheaths, geniculate awn with twisted column, and bearded callus.