10. Cleistogenes hancei Keng, Sinensia. 11: 408. 1940.
北京隐子草 bei jing yin zi cao
Diplachne sinensis Hance, J. Bot. 8: 76. 1870, not Cleisto-genes chinensis (Maximowicz) Keng (1934); C. hancei var. jeholensis (Honda) Kitagawa; C. nakaii (Keng) Honda var. purpurascens Honda; C. serotina (Linnaeus) Keng var. jeholensis Honda; C. serotina var. sinensis (Hance) Keng; C. serotina var. vivipara Honda; Kengia hancei (Keng) Packer; K. serotina (Linnaeus) Packer var. vivipara (Honda) H. Yu & N. X. Zhao.
Culms loosely tufted from a knotty base with scaly buds, erect, 50–100 cm tall, 1–2 mm in diam., usually unbranched, internodes often purple. Leaf sheaths longer or slightly shorter than internodes, usually glabrous, rarely sparsely pilose with tubercle-based hairs, older lower sheaths with disarticulated blades; leaf blades linear, flat, stiffly divaricate to patent, 6–15 × 0.4–0.9 cm, scabrid on both surfaces, sharply acuminate; ligule ca. 0.5 mm. Panicle open, exserted, (6–)10–15 cm; branches widely spreading, clothed in loosely imbricate spikelets, lower branches often with branchlets, lowest 3–8 cm. Spikelets 8–14 mm, green or purplish, florets (3–)5–10; glumes lanceolate, acuminate; lower glume 2–4.2 mm, 1–3-veined; upper glume 3.5–5.7 mm, (1–)3–7-veined; lemmas lanceolate, lowest 5.5–6.5 mm, usually with dark transverse blotches, thinly pilose along lower margins or subglabrous, emarginate; awn (0.6–)1–2(–3) mm; palea keels scabrid. Fl. and fr. Jul–Nov.
Mountain slopes, roadsides, forest margins. Anhui, Fujian, Hebei, Henan, Jiangsu, Jiangxi, Liaoning, Nei Mongol, Shaanxi, Shandong, Shanxi [Russia (Far East)].
This species is one of the largest in the genus, with relatively robust culms, long, broad leaf blades, and an open inflorescence, often with secondary branching. The spikelets typically have multiveined, acuminate glumes, long lemmas, and short awns, but there is much variation and the species is difficult to separate from Cleistogenes hackelii var. nakaii.
The epithet of Diplachne sinensis cannot be used in Cleistogenes because the heterotypic name C. chinensis already exists. The epithets "sinensis" and "chinensis" form homonyms when combined under the same generic name (Saint Louis Code, Art. 53.3 and Ex. 9).
This is a good forage and sand-binding grass.