粗根茎莎草 cu gen jing suo cao

Perennials. Rhizomes long, ± thick, ± hardened, base of shoot with ellipsoid to ovoid tubers. Culms solitary, 8-22 cm tall, 3-angled, smooth, basal sheaths usually disintegrating into fibers. Leaves usually shorter than culm to rarely longer; leaf blade medium green, 2-4 mm wide, usually folded, rarely flat. Involucral bracts 2 or 3, ± erect, leaflike, basal 2 longer than inflorescence. Inflorescence a simple anthela; rays 3 or 4, 0.5-3 cm, each with 3-8 congested spikelets. Spikelets narrowly oblong-ovoid to narrowly ovoid, 6-12 × 2-3 mm, slightly thickened, 10-18-flowered; rachilla narrowly winged. Glumes yellow to brownish yellow on both surfaces variegated with brownish blood-red but middle green, densely imbricate, broadly ovate, ca. 3 mm, papery, 5-7-veined, keel obtuse, margin broadly white hyaline, apex acute to subobtuse. Stamens 3; anthers linear, ca. 1.5 mm; connective apex 0.1-0.2 mm. Style of medium length; stigmas 3. Nutlet dark brown when mature, ellipsoid to subobovoid, ca. 2/3 as long as subtending glume, 3-sided. Fl. and fr. Jul.

Swamps, open grasslands, moist places along seashores; near sea level. Fujian, Guangdong, Hainan, Taiwan, Xisha Qundao [Cambodia, India, Indonesia, Japan (Ryukyu Islands), Laos, Malaysia, Myanmar, Pakistan, Papua New Guinea, Philippines, Sri Lanka, Thailand, Vietnam; NE Australia, Indian Ocean islands, Madagascar, Pacific islands].