Elymus debilis (L. B. Cai) S. L. Chen & G. H. Zhu

Culms slender, 50–60 cm tall, 1–2 mm in diam., 5–7-noded, scabrous; nodes with short, soft hairs. Leaf sheath glabrous; ligule ca. 0.3 mm, apex truncate; leaf blade flat, 7–15 × 0.3–0.5 cm, abaxial surface usually glabrous, adaxial surface scabrous or laxly villous. Spike usually nodding, 6–11 × 0.5–0.7 cm; rachis margin spinose; internodes 4–5 mm. Spikelets green, ca. 9 mm excluding awns, with 2 or 3 florets. Glumes narrowly lanceolate, 2.5–4 mm, subequal or proximal one shorter, 2- or 3-veined, scabrous, or spinose along veins, apex awned; awn 1.5–3 mm. Lemma lanceolate, 5-veined, abaxially scabrous or spinose, apex awned; first lemma 7–8 mm; awn flexuose, slender, 7–10 mm. Palea slightly longer than lemma, spinose along keels, scabrous between keels, apex truncate. Anthers yellow, ca. 1 mm. Caryopsis oblong. Fl. and fr. Jul–Aug.

Gansu (Sunan), Qinghai (Tongde).

* Forests; 2300–3400 m.

Roegneria debilis L. B. Cai, Acta Phytotax. Sin. 34: 327. 1996.