大羊茅 da yang mao

Bromus giganteus Linnaeus, Sp. Pl. 1: 77. 1753; Lolium giganteum (Linnaeus) Darbyshire.

Plant loosely tufted, usually with old brownish sheaths at base; shoots extravaginal. Culms 45–150 cm tall, nodes (1–)2–3. Leaf sheaths glabrous or scabrid; auricles falcate; leaf blades dark green, flat, (10–)15–35(–50) cm × 6–18 mm, midrib conspicuous, margins scabrid, veins 26–36; adaxial to abaxial sclerenchyma strands present; ligule (0.5–)1–1.5(–2.5) mm, margin glabrous. Panicle loose, open, 15–25(–50) cm; branches flexuous, 5–10(–15) cm, paired, unequal, shorter with 3–6 spikelets, longer with 6–9 spikelets, lower 1/3 naked. Spikelets 8–13(–20) mm; florets 3–10; glumes smooth or scabrid; lower glume lanceolate, (3.5–)4–7 mm; upper glume broadly lanceolate, 5–8 mm; rachilla internodes 1.3–1.8 mm, scabrid; lemmas 6–7.5(–9) mm, scabrid, apex entire or slightly notched; awns (6–)10–15(–18) mm; palea keels scaberulous. Anthers 2.5–3 mm. Ovary apex glabrous. Fl. and fr. Jul–Aug. 2n = 42.

Damp shady places along forest margins, grasslands, under shrubs; 1000–3800 m. Sichuan, Xinjiang (Tian Shan), Yunnan [Bhutan, NW India, Kazakhstan, Pakistan, Russia, Tajikistan; SW Asia, Europe; cultivated North America].