Description from
Flora of China
Calamagrostis garwhalensis Hubbard & Bor.
Perennial, densely tufted, rhizomatous; rhizomes spreading. Culms erect, stout, 1–1.3 m tall, 3–4 mm in diam., smooth or slightly scabrid below panicle. Leaf sheaths with auricle on one side; leaf blades broadly linear, flat, 25–45 cm, 5–20 mm wide, adaxial surface scabrid, abaxial surface smooth, apex finely acuminate; ligule 0.5–3 mm, truncate. Panicle loosely contracted, lanceolate in outline, 15–25 cm, nodding, plumose; branches in whorls, bare at base, slightly scabrid. Spikelets silvery-green or tinged pale purple, 5.5–8 mm; glumes linear-lanceolate, subequal or lower glume slightly longer, keel scabrid, apex subulate; callus hairs 2–3 times length of lemma; lemma ca. 1/2 as long as glumes, 2–2.7 mm, 5-veined, deeply 2-toothed by up to 1/3 its length; awn 5–9 mm, arising between teeth, straight, usually projecting beyond glumes; palea slightly shorter than lemma; rachilla extension absent or rudimentary, glabrous. Stamen 1, anther 0.7–1 mm. Fl. and fr. Aug–Sep.
This is a well-defined species with relatively broad leaf blades, a pale, shining panicle, and a deeply toothed lemma. The floret contains a single plump anther.
Grassy slopes in montane regions; 1900–5000 m. Shaanxi, Sichuan, Xizang, Yunnan [Bhutan, N India, Kashmir, N Pakistan].