1. Perotis rara R. Brown, Prodr. 172. 1810.
大花茅根 da hua mao gen
Diplachyrium rarum (R. Brown) Nees; Perotis longiflora Nees; P. macrantha Honda; P. patula Nees; Saccharum rarum (R. Brown) Poiret.
Annual or short-lived perennial. Culms loosely tufted, decumbent at base, 15–40 cm tall. Leaf sheaths glabrous; leaf blades lanceolate to narrowly ovate, flat or margins involute, tough, 1.5–5 cm, 2–5 mm wide, glaucous, glabrous, margins spiny-scabrous, pectinate at base, apex acute. Inflorescence up to 20 cm; spikelets laxly arranged, horizontally spreading, lightly reflexed at maturity; rachis scaberulous-hirtellous. Spikelets 3.5–4.5 mm (excluding awns); basal callus 0.5–1.5 mm, narrowly obconical, flattened, sometimes laterally pubescent; glumes linear-lanceolate, back evenly scaberulous-hirtellous with short white hairs, midvein scabrous with longer prickles toward awn, apex gradually tapering into awn; awn 1–2.5 cm; lemma 1.2–1.5 mm. Anthers ca. 0.6 mm. Caryopsis terete, subulate, ca. 2.5 mm. Fl. and fr. Jun–Nov.
Sandy seashores. Fujian, Guangdong, Guangxi, Hainan, Taiwan [New Guinea, Philippines, Thailand, Vietnam; Australia].
This species is at the northern limit of its range in S China, and can be distinguished by its much more loosely arranged inflorescence of very narrow spikelets, with the tips drawn out into longer awns.