Description from Flora of China
Fimbristylis crassipes Palla (1909), not Boeckeler (1858); F. gynophora C. B. Clarke.
Annuals. Culms grayish green, tufted, 7-60 cm tall, slender, flatly 3-angled, smooth, striate, with few leaves at base. Leaves shorter than culm; leaf blade ca. 1 mm wide, flat but sometimes involute, slightly stiff, margin apically ciliate. Involucral bracts absent or only 1, linear, 0.7-10 cm, erect, longer than inflorescence. Inflorescences reduced to 1(or 2) terminal spikelet. Spikelet ovoid, oblong-ovoid, or narrowly oblong-ovoid, 8-30 × 4-8 mm, terete, many flowered. Glumes spirally imbricate, brown with short rust-colored lines, ovate, broadly ovate, or subelliptic, 5-7 mm, membranous, abaxially with many veins, not keeled, apex obtuse and mucronate. Stamens 3; anthers linear, 2-2.5 mm. Style long, compressed, ciliate, basally slightly inflated; stigmas 2. Nutlet brown, stipitate, globose-obovoid, 1.5-1.7 mm, flatly biconvex, slightly shiny and with hexagonal reticulation. Fl. Jun-Aug, fr. Sep-Oct. 2n = 10.
Slopes, valleys, marshes, streamsides, watersides, seashores, salt marshes; near sea level to 1200 m. Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hebei, Henan, W Hunan, Jiangsu, Liaoning, Shaanxi, Shandong, Shanxi, Taiwan, Xisha Qundao, Zhejiang [Japan, Korea, Vietnam].