4. Cleistogenes mucronata Keng ex P. C. Keng & L. Liu, Acta Bot. Sin. 9: 70. 1960.
小尖隐子草 xiao jian yin zi cao
Cleistogenes gracilis Keng ex P. C. Keng & L. Liu; Ken-gia gracilis (Keng ex P. C. Keng & L. Liu) Packer; K. mucro-nata (Keng ex P. C. Keng & L. Liu) Packer.
Culms densely tufted, clothed at base in old sheath remnants, lacking basal scaly buds, erect, wiry, 30–60 cm tall, 0.5–0.8 mm in diam., unbranched. Leaf sheaths longer than internodes, glabrous but pilose at mouth; leaf blades stiff, patent, longest at culm center, here 3–7 × 0.1–0.2 cm, uppermost 1–2 cm, glabrous, adaxial surface and margins scabrid, abaxial surface smooth, lower blades disarticulating; ligule 0.2–0.3 mm. Panicle open, 5–12 cm, exserted from uppermost leaf sheath; branches laxly ascending or spreading, racemose or lower branches with branchlets, lowest branch 4–8 cm. Spikelets oblong, (6–)8–14 mm, yellowish brown or purplish green, florets 3–8; glumes lanceolate, acute; lower glume 1.6–3.5 mm, 1(–3)-veined; upper glume 3.5–4.5 mm, 1–3-veined; lemmas lanceolate, lowest 4–5 mm, loosely pilose near margins; mucro 0.1–0.2 mm; palea keels ciliolate. Anthers 2–3 mm. Fl. and fr. Jul–Sep.
* Rocky hills, mountain slopes. Gansu, Henan, Nei Mongol, Ningxia, Qinghai, Shaanxi, Shanxi.
This is a densely tufted, wiry species with clumps of old sheaths at the base, numerous stiff, patent, narrow leaf blades, the uppermost very short, and exserted, flexuose panicles of spikelets with relatively short, inconspicuously mucronate lemmas. It is close to Cleistogenes festuca-cea and perhaps intergrades with that species through forms with slightly longer lemmas and awnlets.