11. Agrostis nervosa Nees ex Trinius, Mém. Acad. Imp. Sci. Saint-Pétersbourg, Sér. 6, Sci. Math., Seconde Pt. Sci. Nat. 6, 4(3–4): 328. 1841.
泸水剪股颖 lu shui jian gu ying
Agrostis clarkei J. D. Hooker; A. limprichtii Pilger; A. lushuiensis B. S. Sun & Y. Cai Wang; A. schneideri Pilger; A. schneideri var. brevipes Keng ex Y. C. Yang; A. sikkimensis Bor; A. taliensis Pilger.
Perennial, tufted. Culms very slender, erect, 20–30(–50) cm tall, 0.5–0.8 mm in diam., 1–4-noded. Leaf sheaths loose, smooth; leaf blades narrowly linear to setaceous, flat or involute, 3–13 cm × 0.8–3 mm, abaxial surface smooth, adaxial surface scabrid; ligule 0.5–3 mm, back smooth or scaberulous, apex obtuse. Panicle open to laxly contracted, narrowly lanceolate to ovate in outline, 3–15 cm; branches 2–5 per node, very fine, ascending to spreading, 1–6.5(–8) cm, smooth or almost so, bare below middle. Spikelets 1.7–3.2 mm, dark purple or purplish green; glumes lanceolate, unequal, lower glume 1.7–3.2(–3.5) mm, keel scabrid above middle, long acuminate, upper glume 1.6–2.9 mm, apex acute; callus glabrous; lemma 2/3–4/5 spikelet length, awnless or a fine awnlet up to 0.6 mm below apex, apex obtuse or emarginate; palea 0.2–0.5 mm, 0.2–0.4 lemma length. Anthers 0.5–0.75 mm. Fl. and fr. Aug–Sep.
Grassy or stony mountain slopes, meadows, broad-leaved woodlands, bamboo forests; 2000–4000 m. Guizhou, Sichuan, Xizang, Yunnan [Bhutan, India (Darjeeling, Sikkim), N Myanmar, Nepal].
This is a variable species with a wide range of spikelet size, but usually with clearly unequal, purple glumes and awnless lemmas. The name Agrostis sikkimensis refers to slender, delicate variants with small spikelets and very fine leaf blades, often growing among moss on rocks. There is continuous variation to taller forms with larger spikelets growing in meadows and woodlands. Forms with a short, straight, subapical awnlet (A. limprichtii, A. lushuiensis) may have arisen by hybridization with A. sinorupestris.
Agrostis szechuanica (Y. C. Tong ex Y. C. Yang) L. Liu (Vasc. Pl. Hengduan Mts. 2: 2247. 1994; A. clavata Trinius var. szechuanica Y. C. Tong ex Y. C. Yang, Bull. Bot. Res., Harbin 4(4): 99. 1984) may belong here. The type, from Sichuan (Hanyuan), has not been seen. It is also reported from Yunnan.