Description from Flora of China
Zizania terrestris Linnaeus, Sp. Pl. 2: 991. 1753; Scleria doederleiniana Boeckeler; S. elata Thwaites; S. elata var. latior C. B. Clarke.
Perennials, stoloniferous. Rhizomes woody, with dark purple scales. Culms sparse, 0.6-3 m tall, 4-7 mm wide, 3-angled, often scabrous, glabrous. Leaf sheaths 1-8 cm, papery; basal 2 or 3 sheaths on culm purplish red, not winged; sheaths at middle part of culm with wings 1-3 mm wide; contraligule semicircular, short, usually barbate, barbs purple; leaf blade linear, 30-40 cm × 6-10 mm, papery, slightly scabrous, glabrous. Involucral bracts leaflike, basalmost to 40 cm, sheathing; bractlets setaceous, basally auriculate, auricles slightly hispid. Inflorescences paniculate, with 1-3 distant branches; branches 3-8 × 1.5-6 cm. Spikelet 1(or 2) in a cluster, entirely unisexual, oblong-ovoid to narrowly ovoid, apex truncate to acuminate. Glumes of male spikelets 2-3 mm, thickly membranous, basal ones keeled and with rust-colored short lines, apical ones pale colored and scarious. Female spikelets usually growing at base of branch; glumes broadly ovate to ovate-lanceolate, 2-4 mm wide, sometimes with rust-colored short lines, keeled, apex apiculate. Male spikelets 3-flowered. Male flowers: anthers linear. Female flowers: stigmas 3. Disk yellow, ca. 1.8 mm in diam., slightly 3-lobed to barely lobed; lobes semicircular, flat, margin reflexed. Nutlet white or pale brown, spherical to ovoid, ca. 2.5 mm in diam., sometimes ± 3-sided, reticulate, slightly hispid, apex tipped. Fl. and fr. May-Oct.
Slopes, dry or moist places, valleys, stream margins, under shrubs, open woods, beside farms or roads; near sea level to 2000 m. Chongqing, Fujian, Guangdong, Guangxi, Guizhou, Hainan, S Hunan, Jiangsu, Jiangxi, SE Sichuan, Taiwan, SE Xizang, Yunnan, Zhejiang [Bhutan, Cambodia, India, Indonesia, S Japan, Kashmir, Laos, Malaysia, Myanmar, Nepal, Papua New Guinea, Philippines, Sri Lanka, Thailand, Vietnam; N Australia].