4. Ischaemum ciliare Retzius, Observ. Bot. 6: 36. 1791.
细毛鸭嘴草 xi mao ya zui cao
Andropogon patentivillosus Steudel; Ischaemum ciliare var. villosum (Nees) Hackel; I. indicum (Houttuyn) Merrill var. breviaristatum Zhao; I. indicum var. guangdongense Zhao; Spodiopogon obliquivalvis Nees var. villosus Bentham; S. vil-losus Nees.
Perennial. Culms slender, loosely tufted, erect, spreading or prostrate and rooting at lower nodes, up to 60 cm tall, nodes bearded. Leaf sheaths sparsely to densely pilose with tubercle-based hairs, or glabrous; leaf blades linear-lanceolate, 5–15 × 0.3–1 cm, tuberculate-villous or sometimes glabrous, base contracted, apex acuminate; ligule 1–2 mm. Racemes terminal, paired, often slightly separated, 2–9 cm; rachis internodes and pedicels oblong, triquetrous, ciliate along angles. Sessile spikelet obovate-oblong, 4–6 × 1.2–1.5 mm; lower glume smooth, glossy, leathery with rounded flanks in lower half, upper half flat, papyraceous, sometimes wrinkled, asperulous, flanks keeled, winged, wings 0.2–0.7 mm wide, forming 2 rounded lobes at apex; upper glume swollen and keeled above middle, keel narrowly winged, apex shortly awned; awn of upper lemma 1–1.5 cm. Pedicelled spikelet laterally compressed; lower glume with a single median winged keel; upper lemma awned.
Moist meadows, field margins, hill thickets; near sea level to 1300 m. Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hubei, Hunan, Jiangsu, Sichuan, Taiwan, Yunnan, Zhejiang [India, Indonesia, Malaysia, Myanmar, Sri Lanka, Thailand, Vietnam; introduced in America].
This grass has been widely known as Ischaemum indicum (Houttuyn) Merrill (Phleum indicum Houttuyn), but that name in fact refers to a species of Polytrias. Ischaemum ciliare is a very variable species, widespread in tropical Asia, and a number of varieties has been described over its range.