Description from Flora of China
Pollinia ciliata Trinius, Mém. Acad. Imp. Sci. St.-Pétersbourg, Sér. 6, Sci. Math. 2: 305. 1833; Andropogon biaristatus Steudel; A. formosanus Rendle var. minor Rendle; Microstegium biaristatum (Steudel) Keng; M. biforme Keng; M. ciliatum var. formosanum (Hackel) Honda; M. ciliatum var. integrum Ohwi; M. formosanum (Hackel) A. Camus; Pollinia ciliata Trinius var. formosana (Hackel) Honda; P. formosana (Hackel) Hayata; P. monantha var. formosana Hackel.
Perennial. Culms wiry, creeping, 1 m or more long, pubescent below inflorescence, nodes glabrous or pilose. Leaf sheaths pilose or glabrous, one margin ciliate; leaf blades linear-elliptic, 6–16 × 0.5–1.5 cm, adaxial surface thinly pilose with short tubercle-based hairs, abaxial surface softly pilose, apex acuminate into a setaceous point; ligule 1–2 mm. Racemes 3–15, flexuous, usually pale green, fastigiate, 6–10 cm; rachis internodes linear, slightly inflated upward, shorter than spikelet, margins ciliate. Sessile spikelet 3–4 mm; callus hairs 1–1.5 mm; lower glume narrowly lanceolate, back sharply grooved at lower midline, glabrous or scaberulous toward apex, 2-veined between keels, upper keels stiffly pectinate-ciliate, apex 2-toothed; upper glume sharply keeled, apex acuminate into a 0.3–3 mm hairlike awnlet; lower lemma absent or very small; upper lemma linear or lanceolate, occasionally broader, 0.5–1 mm, apex usually entire; awn 1–2 cm, flexuous with weakly developed column and fine hairlike apex. Anthers 3, 0.8–1.5 mm. Fl. and fr. Sep–Dec.
This species is closely related to Microstegium fasciculatum, and the two are difficult to distinguish, at least in the herbarium. Microstegium ciliatum is a more slender species, forming loose mats rather than large, rambling colonies, usually with pale green rather than purplish inflorescences. The spikelets are narrower, with obviously longer, flexuous awns and an awned upper glume. Occasionally some spikelets in an inflorescence have tiny anthers (the basis of M. biforme).
The name "Ischnochloa monostachya L. Liu" (Fl. Reipubl. Popularis Sin. 10(2): 65. 1997) has been placed in synonymy under this species (in Fl. Yunnan. 9: 637. 2003), but was not validly published because no Latin description was provided.
Open woodlands, shady banks, pathsides, forming loose mats. Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hunan, Jiangxi, Sichuan, Taiwan, Yunnan [Bhutan, India, Malaysia, Myanmar, Nepal, Sri Lanka, Thailand, Vietnam].