Description from Flora of China
Elymus yilianus S. L. Chen, nom. illeg. superfl.
Culms laxly tufted, erect or geniculate at base, ca. 70 cm tall. Leaf sheath smooth; leaf blade flat, 4–12 × 0.3–0.5 cm, scabrous or abaxial surface smooth. Spike pendulous, lax, slender, 10–15 cm; rachis margin scabrous or ciliolate. Spikelets 2 per node, glaucous or purplish glaucous, 13–15 mm, with 4–6 florets. Glumes oblong-lanceolate or ovate-lanceolate, 3–4 mm, 1–3-veined, scabrous along veins, apex usually pointed. Lemma lanceolate, puberulent throughout or glabrous at middle part; first lemma 8–9 mm, apex with awn (1–)2–5 mm. Palea equaling lemma, ciliolate along keels, puberulent between keels, apex narrowed. Fl. and fr. summer. 2n = 42*.
"Elymus brachyaristatus" (Löve, Feddes Repert. 95: 449. 1984) was not validly published because it was given as a nomen novum based on "Clinelymus breviaristatus" (Keng, Fl. Ill. Pl. Prim. Sin. Gram. 423. 1959), which was itself not validly published because no Latin description was provided (Saint Louis Code, Art. 36.1). Moreover, Löve's supposed blocking name, E. breviaristatus (Hitchcock) A. Löve (loc. cit. 471. Oct 1984), is in fact an illegitimate later homonym (Art. 53.1) because E. breviaristatus Keng ex P. C. Keng had already been validly published in July 1984.
* Mountain slopes. Ningxia, Qinghai, Sichuan, Xinjiang.