Elymus durus (Keng) S. L. Chen

Löve (Feddes Repert. 95: 448. 1984) published Elymus sclerus as a nomen novum for Brachypodium durum, but the supposed blocking name, "Elymus durus Hedw. ex Steud., 1854" (Steudel, Nomencl. Bot., ed. 2, 1:550, 551. 1840), was merely cited as a synonym by Steudel and was therefore not validly published under Art. 34.1(c) of the Saint Louis Code. Under Art. 11.4, the correct name in Elymus at specific rank is E. durus. Löve's name was therefore nomenclaturally superfluous when published and is illegitimate under Art. 52.1.

Culms solitary or tufted, usually geniculate or with swollen nodes at base, 55–80 cm tall; nodes glaucous or purplish green, glabrous. Leaf sheath sometimes retrorsely pubescent; leaf blade flat or involute, 6–20(–25) × 0.1–0.45 cm, stiff, abaxial surface smooth or puberulent, adaxial surface scabrous or laxly puberulent. Spike nodding, 5–11 cm. Spikelets 1 per node, green or purplish green, 1.6–2.2 cm, with (3 or)4–7 florets; pedicel 0.8–1.5(–2) mm, glabrous or puberulent. Glumes lanceolate, scabrous along veins, margin thin, apex acute, acuminate, or pointed; proximal glume 3–4(–7) mm, 1–5-veined; distal glume 5–9 mm, 3–5-veined. Lemma lanceolate, hispidulous or scabrous; first lemma ca. 11 mm; awn reflexed, 1.5–2.8 cm, scabrous. Palea subequaling lemma, ciliate along keels, puberulent between keels. Anthers black, ca. 1.5 mm. Fl. and fr. late summer. 2n = 28*.

Gansu, Qinghai, Sichuan, Xinjiang, Xizang, Yunnan.

* Mountain meadows; 3700–4200 m.

Basionym: Brachypodium durum Keng, Sunyatsenia 6: 54. 1941; Elymus sclerus A. Löve, nom. illeg. superfl.; Roegneria dura (Keng) Keng; R. dura var. variiglumis Keng; R. tschimganica (Drobow) Nevski var. variiglumis (Keng) L. B. Cai.