九顶草 jiu ding cao

Enneapogon borealis (Grisebach) Honda; E. brachystachyus (Jaubert & Spach) Stapf; E. desvauxii subsp. borealis (Grisebach) Tzvelev; E. jinjiangensis B. S. Sun & S. Wang; Pappophorum boreale Grisebach; P. brachystachyum Jaubert & Spach.

Perennial. Culms densely tufted, wiry, usually geniculate at base, 5–35 cm tall, pubescent. Basal leaf sheaths tough, whitish, enclosing cleistogamous spikelets, finally becoming fibrous; leaf blades usually involute, filiform, 2–12 cm, 1–3 mm wide, densely pubescent or the abaxial surface with longer white soft hairs, finely acuminate. Panicle gray, dense, spikelike, linear to ovate, 1.5–5 × 0.6–1 cm. Spikelets with 3 florets, 5.5–7 mm; glumes pubescent, 3–9-veined, lower glume 3–3.5 mm, upper glume 4–5 mm; lowest lemma 1.5–2 mm, densely villous; awns 2–4 mm, subequal, ciliate in lower 2/3 of their length; third lemma 0.5–3 mm, reduced to a small tuft of awns. Anthers 0.3–0.6 mm. Fl. and fr. Aug–Nov. 2n = 36.

Dry hill slopes; 1000–1900 m. Anhui, Gansu, Hebei, Liaoning, Nei Mongol, Ningxia, Qinghai, Shanxi, Xinjiang, Yunnan [India, Kazakhstan, Kyrgyzstan, Mongolia, Pakistan, E Russia; Africa, America, SW Asia].

This species is one of the most widespread in the genus and is the only one to develop cleistogamous spikelets within the basal leaf sheaths. Mature grains can often be found at the base of the plant.