Trisetum bifidum (Thunb.) Ohwi

Growing in high mountain area at 2000 m.

Perennial, densely tufted; culms erect, 35-70 cm tall, 1-2 mm in diameter, ligule membranous, tongue-shaped, 0.2 -1.5 mm; leaf-blades 10-20 cm long, 3-4 mm wide. Panicle slightly open, 10-20 cm long, often inclined above, shiny. Spikelet 2-3-flowered, 6-9 mm long, rachilla joints 1.5 mm long; glumes chartaceous, lanceolate, unequal, lower glume 2-3.5 mm long, 1-nerved, upper glume 5-7 mm long, 3-nerved; lemma 5-8 mm long, chartaceous, scabrous, the apex shallowly bifid with acuminate lobes awn arising from the sinus, 6-10 mm long, geniculate; palea membranous, 3.5-4.5 mm long, ciliate on keel, the apex deeply bifid.

Perennial, tussocky. Culms erect or geniculate at base, 30–100 cm tall, glabrous, 2–5-noded. Leaf sheaths usually shorter than internodes, glabrous or pilose, margins joined in lower part; leaf blades flat, soft, up to 20 cm, 3–6 mm wide, glabrous or occasionally pilose; ligule 0.5–2 mm. Panicle lax, oblong to lanceolate-oblong in outline, 10–25 cm, often nodding, yellow-green or brown green; branches 2 or 3 at basal node, scaberulous, lowest up to 10 cm. Spikelets 6–8 mm, florets 2 or 3; rachilla hairs 0.2–0.5 mm; glumes unequal, lower glume 2–3.5 mm, upper glume 4–7 mm, apex acuminate; callus pubescent; lemmas 5–7 mm, firm, golden brown, punctate-scabrid, awned from upper 1/4, apex 2-toothed, teeth 1–2 mm, aristulate; awn 7–10 mm, fine, strongly recurved near base, not twisted; palea 1/2(–2/3) length of lemma, keels conspicuously convex, ciliolate. Anthers 0.5–1 mm. Fl. Apr–Jun.

Japan, Korea and China.

Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Shaanxi, Shandong, Sichuan, Taiwan, Xizang, Yunnan, Zhejiang [Japan, Korea, New Guinea].

Forests, roadsides, moist grassy ditch banks; 500–2500 m.

Bromus bifidus Thunberg in Murray, Syst. Veg., ed. 14, 119. 1784; Avena bifida (Thunberg) P. Beauvois; Trisetum flavescens (Linnaeus) P. Beauvois var. bifidum (Thunberg) Makino; T. flavescens var. macranthum Hackel; T. flavescens var. papillosum Hackel.