3. Anthoxanthum potaninii (Tzvelev) S. M. Phillips & Z. L. Wu, Novon. 15: 476. 2005.
松序茅香草 song xu mao xiang cao
Hierochloë potaninii Tzvelev, Rast. Tsentr. Azii 4: 35. 1968.
Plant loosely tufted, shortly rhizomatous, brown scales at base. Culms 50–120 cm tall, 4-noded, nodes black-brown. Leaf sheaths glabrous, smooth or scaberulous, shorter than internodes below and longer above; leaf blades broadly linear, 15–25 cm, 6–15 mm wide, both surfaces scabrid; ligule up to 1 cm, lanceolate. Panicle fairly loose, 10–22 × 2–6 cm; branches smooth. Spikelets 3.5–6 mm; glumes unequal, lower glume about half spikelet length, 1-veined, upper glume a little shorter than spikelet, 3-veined; lower florets staminate, lemmas ca. 5 mm, scabrid on back, margins ciliate, apex emarginate; first lemma awnless or mucronate; second lemma with subapical awn up to 4 mm; bisexual floret similar to staminate but smooth on back, scabrid near apex; palea 1(–2)-veined; anthers 2–3.5 mm. Fl. Jun.
* Grassy places in mountain valleys, forest margins and among shrubs; 2500–3000 m. S Gansu, W Sichuan.
Anthoxanthum laxum (R. Brown ex J. D. Hooker) Veldkamp (Hierochloë laxa R. Brown ex J. D. Hooker) has been confused with this species. Anthoxanthum laxum occurs on high-mountain ledges and in alpine pastures above 3000 m in E Afghanistan, Kashmir, Nepal, and N Pakistan. It can be distinguished by its smooth leaf blades, subequal glumes, and pilose or hirsute apex of the bisexual floret.