Description from Flora of China
Agrostis arisan-montana var. megalandra Y. C. Yang; A. megathyrsa Keng ex P. C. Keng var. angustispicata D. Z. Ma & J. N. Li; A. perarta Keng.
Perennial, loosely tufted. Culms geniculate at base, rooting at lower nodes, 40–100 cm tall, 1–1.7 mm in diam., 3–6-noded. Leaf sheaths smooth; leaf blades linear, soft, 5–14 cm × 2–6 mm, both surfaces scabrid, abaxial surface densely so, apex acuminate; ligule 2–3.5 mm, back scabrid, apex obtuse. Panicle contracted, narrowly lanceolate-oblong in outline, 10–20 cm, much branched; branches 3 per node or rebranched at base, narrowly ascending, longest 5–8 cm, scabrid, bearing spikelets from base. Spikelets 1.9–2.3 mm, yellowish green often with purplish tinge; glumes narrowly ovate-oblong, subequal, keel scabrid, apex subacute or acute; callus glabrous; lemma ca. 3/4 spikelet length, midvein terminating from slightly below middle to apex, awnless, apex broadly rounded, minutely denticulate; palea 0.35–0.75 mm, 0.2–0.4 lemma length. Anthers 0.5–0.8 mm. Fr. Jul.
In this species the lemma is awnless, with the midvein terminating anywhere from slightly below the middle up to the apex, varying even within the same panicle. The length of the palea is also rather variable, sometimes almost reaching the middle of the lemma.
Agrostis arisan-montana is close to A. micrantha, but tends to have a narrower panicle and more sharply acute glumes. It is also close to A. infirma, but with a more open panicle. The relationship between these three taxa, extending from the Himalayas through China into SE Asia, requires further investigation. Agrostis fukuyamae and A. sozanen-sis also belong to this group.
* Grassy mountain slopes; 900–3200 m. Guangxi, Henan, Ningxia, Shaanxi, Sichuan, Taiwan, Yunnan.