钝基草 dun ji cao

Timouria saposhnikovii Roshevitz in B. Fedtschenko, Fl. Aziatsk. Ross. 12: 174. 1916; Stipa saposhnikovii (Roshevitz) Kitagawa.

Perennial, forming small tufts. Culms erect, 25–50 cm tall, 1–1.5 mm in diam., 2–3-noded. Leaf sheaths shorter than internodes, tightly overlapping, smooth; leaf blades convolute, setaceous, 5–15 cm, 1–2.5 mm wide, abaxial surface smooth; ligule 0.2–0.7 mm. Panicle linear, spikelike, dense, 3–7 × 0.6–0.8 cm; branches appressed to axis, 0.5–2 cm, scabrid, with spikelets to base. Spikelets 5–6 mm, yellowish green; glumes keeled, lanceolate, slightly unequal, lower glume 5–6 mm, upper glume 4.5–5 mm, prominently 3-veined, keel scabrid, apex finely acuminate; callus obtuse, ca. 0.3 mm, lemma elliptic, 2.5–3.5 mm, back pilose, apex 2-toothed, teeth ca. 0.2 mm; awn ca. 0.4 cm, caducous, straight or slightly twisted at base, scabrid. Anthers 1.6–2 mm, glabrous at apex. Fl. and fr. Jul–Sep.

Dry stony slopes, steppe regions; 1500–3500 m. Gansu, Nei Mongol, Ningxia, Qinghai, Xinjiang [Kazakhstan, Kyrgyzstan, Mongolia, Uzbekistan].

This grass is distinctive in the genus on account of its keeled, prominently 3-veined glumes. It is sometimes placed in the separate genus Timouria, but resembles Achnatherum in its elliptic floret and 2-toothed lemma.