9. Rhynchospora submarginata Kükenthal, Bot. Jahrb. Syst. 74: 498. 1949.
类缘刺子莞 lei yuan ci zi guan
Rhynchospora marginata C. B. Clarke (1908), not (Liebmann) Steudel (1855).
Annuals. Roots fibrous. Culms tufted, erect, 10-60 cm tall, slender, 3-angled, smooth. Leaves basal and 1 or 2 cauline in lower 1/3 of culm, 1/4-3/4 as long as culm; leaf blade linear, 2-2.5 mm wide, glabrous or pubescent, margin slightly involute, apex acuminate. Involucral bracts 3-6, leaflike, to 15 cm, base dilated and densely ciliate, apically slightly involute, sheathless, apex acuminate. Inflorescence a single terminal head, 1.2-2 cm in diam. Spikelets narrowly ovoid, 5-6 mm, shiny, 2-flowered. Glumes 6 or 7, rust-colored, ovate-lanceolate to elliptic-lanceolate; basal 3 or 4 empty, ± smaller; middle glumes ca. 4 mm, each with 1 female flower; apical 2 or 3 glumes each with a male flower. Perianth bristles 6, longer than nutlet and style base, antrorsely scabrous. Stamens 2 or 3; anthers linear, ca. 2 mm; connective slightly evident, reddish, pubescent. Nutlet blackish, linear-oblong, ca. 3.5 mm, sub-biconvex, whitish setulose to almost glabrous; persistent style base pale brown, ca. 1/2 as long as nutlet. Fl. and fr. Jun-Oct.
Sandy grasslands, paddy fields. Hainan [India, Indonesia, Malaysia, Papua New Guinea, Thailand, Vietnam; N Australia].