5. Cleistogenes festucacea Honda, Rep. First Sci. Exped. Manchoukuo, Sect. IV. 4: 98. 1936.
薄鞘隐子草 bao qiao yin zi cao
Cleistogenes foliosa Keng; C. kitagawae Honda var. folio-sa (Keng) S. L. Chen & C. P. Wang; C. striata Honda; Kengia festucacea (Honda) Packer; K. foliosa (Keng) Packer; K. kitagawae (Honda) Packer var. foliosa (Keng) H. Yu & N. X. Zhao; C. longiflora Keng ex P. C. Keng & L. Liu.
Culms densely tufted, base with old sheath remnants, lacking basal scaly buds, erect, wiry, 30–45 cm tall, 0.5–0.8 mm in diam., unbranched. Leaf sheaths longer than internodes, glabrous but pilose at mouth; leaf blades flat or involute when dry, ascending to stiffly spreading, 4.5–7 × 0.12–0.2(–0.27) cm, scaberulous especially toward the subulate-involute apex, lower blades disarticulating; ligule ca. 0.5 mm. Panicle lax, slightly flexuose, 7–10 cm, usually shortly exserted from uppermost leaf sheath; branches mostly narrowly ascending, few-spiculate, simple, lowest branch 3–5 cm. Spikelets 6–9 mm, pale green or purple-tinged, florets 2–5; glumes narrowly lanceolate, 1–3(–5)-veined, acuminate; lower glume 1.4–4.3 mm; upper glume (2.5–)3.5–5.7 mm; lemmas narrowly lanceolate, lowest (4.5–)5–6.5 mm, thinly pilose near margins; awn (0.2–)1–2(–2.5) mm; palea keels ciliolate. Anthers 2.2–2.5 mm. Fl. and fr. Aug–Oct.
* Gansu, Hebei, Nei Mongol, Ningxia, Shandong, Shanxi.
This species has a characteristic, densely tufted habit with very slender, wiry culms, narrow, spreading leaf blades and a loose, rather flexuose panicle. However, the spikelet parts are variable, which has led to the application of several different species names. The glumes are usually acuminate and 1-veined or faintly 2- or 3-veined. The name Cleistogenes striata was given to an unusually strongly veined variant with up to 5 prominent veins in the glumes and 7 veins in the lemmas. The length of the lemmas and awns is also variable, sometimes even within a single panicle.