Elymus alienus (Keng) S. L. Chen

The names Roegneria aliena and R. foliosa have equal priority, but in Elymus only E. alienus is validly published. Chen (Bull. Nanjing Bot. Gard. 1987: 9. 1988) did not validly publish the combination "E. foliosus" because the place of valid publication of the basionym was not cited (Saint Louis Code, Art. 33.3). Instead, R. foliosa was cited from Keng (Fl. Ill. Pl. Prim. Sin. Gram. 366. 1959), where the name was not validly published because no Latin description was provided (Art. 36.1).

Plants usually with short, underground rhizomes. Culms laxly tufted, (30–)60–90 cm tall, 3- or 4(–6)-noded. Leaf sheath glabrous or retrorsely pubescent; leaf blade flat, 12–20 × 0.4–0.9 cm, abaxial surface glabrous, adaxial surface pubescent. Spike erect or slightly curved, 7–15 cm. Spikelets 1 per node, green or purplish green, 14–17 mm excluding awns, with 4–6 florets; rachilla puberulent; internodes 1–2.5 mm. Glumes oblong-lanceolate, 3–5(or 6)-veined, smooth or scabrous along veins, apex acute or acuminate; proximal glume 7–8 mm; distal glume 8–10 mm. Lemma lanceolate, smooth and glabrous abaxially, but scabrous or puberulent along veins and near margin; first lemma 9–10 mm; callus with hairs 0.4–0.6 mm; awn straight or slightly reflexed, 10–25 mm. Palea slightly shorter than lemma, ciliate along keels distally, apex obtuse. Anthers ca. 2.5 mm. Fl. and fr. Jun–Aug.

Hebei, Henan, Nei Mongol, Shanxi.

* Moist valleys, roadsides; ca. 1100 m.

Roegneria aliena Keng, Acta Univ. Nankin. Sci. Nat. 1963(1): 31. 1963; R. barbicalla (Ohwi) Keng & S. L. Chen var. foliosa (Keng) L. B. Cai; R. foliosa Keng.

Elymus alienus là một loài thực vật có hoa trong họ Hòa thảo. Loài này được (Keng) S.L.Chen mô tả khoa học đầu tiên năm 1997.