17. Digitaria longiflora (Retzius) Persoon, Syn. Pl. 1: 85. 1805.
长花马唐 chang hua ma tang
Paspalum longiflorum Retzius, Observ. Bot. 4: 15. 1786; Digitaria propinqua (R. Brown) P. Beauvois; Panicum longi-florum (Retzius) J. F. Gmelin; P. parvulum Trinius, nom. illeg. superfl.; P. propinquum R. Brown; Syntherisma longiflora (Retzius) H. C. Skeels.
Annual or short-lived perennial, usually with slender, many-noded stolons. Culms ascending, leafy, 10–40 cm tall. Leaf sheaths pubescent or glabrous; leaf blades broadly linear, 2–5 × 0.2–0.4 cm, glabrous or papillose-pilose at base, apex acute; ligule 1–1.5 mm. Inflorescence digitate; racemes 2–3, arching at maturity, 2–5 cm; spikelets ternate; rachis ribbonlike, winged, 0.5–0.8 mm broad, midrib low and rounded; pedicels terete, smooth, with discoid tips. Spikelets elliptic, 1.2–1.5 mm, apex acuminate, hairs verrucose; lower glume absent; upper glume as long as spikelet, 5-veined, densely appressed-pubescent; lower lemma as long as spikelet, 7-veined, glabrous between middle and lateral veins, otherwise pubescent; upper lemma yellowish brown or pale gray, apex acuminate. Anthers 0.6–0.8 mm. Fl. and fr. Apr–Oct. 2n = 18.
Field margins, grasslands, weedy places; 600–1100 m. Fujian, Guangdong, Guizhou, Hainan, Hunan, Jiangxi, Sichuan, Taiwan, Yunnan [Bhutan, India, Indonesia, Malaysia, Myanmar, Nepal, Pakistan, Sri Lanka, Thailand, Vietnam; Old World tropics, America].
Digitaria fuscescens (J. Presl) Henrard differs from D. longiflora only by its glabrous spikelets and slightly longer, fractionally exserted upper floret. Most likely it is simply a glabrous variant of D. longiflora. It is widespread throughout the tropics, and although reported from S China, no specimens have been seen.