Description from Flora of China
Calamagrostis moupinensis Franchet, Nouv. Arch. Mus. Hist. Nat., ser. 2, 2: 106. 1888.
Perennial, loosely tufted, shortly rhizomatous. Culms erect, 40–70 cm tall, 2–3 mm in diam., 3–4-noded. Leaf sheaths retrorsely pubescent or glabrous; leaf blades flat or involute, 10–25 cm, 2–6 mm wide, both surfaces scabrid; ligule ca. 0.5 mm, truncate. Panicle contracted or slightly loose, base usually included in terminal leaf sheath, 8–14 × 1.5–3 cm; branches in whorls of 2–5, very slender, densely spiculate, erect or narrowly ascending. Spikelets 3.5–4 mm, yellowish green or purplish; glumes narrowly lanceolate, subequal, lower glume 1-veined, upper glume 3-veined, scabrid, apex acute; callus hairs as long as lemma; lemma ca. 3 mm, apex bidentate or 2-lobed to awn insertion; awn arising below apex or between lobes, 5–6 mm, slender, almost straight, much exceeding spikelet; palea 2/3 as long as lemma; rachilla ca. 0.5 mm, sparsely penicillate, 2.5–3.5 mm including hairs. Anthers ca. 1.2 mm. Fl. Aug–Sep. 2n = 28*.
* Grassy places in montane forests; 1300–2600 m. Sichuan.