29. Fimbristylis sieboldii Miquel ex Franchet & Savatier, Enum. Pl. Jap. 2: 118. 1877.
锈鳞飘拂草 xiu lin piao fu cao
Perennials. Rhizomes short or well developed and horizontally creeping, woody. Culms grayish green, tufted, 10-65 cm tall, slender, flatly 3-angled, smooth, base thicker, with few leaves. Basal leaves with sheaths only and grayish brown. Leaves apically on culm with a blade, 1/3 or less as long as culm; leaf blade often linear, ca. 1 mm wide, folded. Involucral bracts 2 or 3, shorter to slightly longer than inflorescence, suberect, base slightly broader. Inflorescence a simple or rarely subcompound anthela; rays less than 10 mm. Spikelets solitary, oblong-ovoid, oblong, or narrowly oblong-ovoid, 10-17 × 3-4 mm, terete, densely many flowered, apex acute to rarely obtuse. Glumes grayish brown with dark brown lines at middle, ovate to elliptic, 3-4 mm, submembranous, apically with grayish white hairs, abaxially prominently keeled, margin ciliate, apex obtuse and apiculate. Stamens 3; anthers linear. Style long and flat, basally broader; stigmas 2. Nutlet brown to blackish brown when mature, shortly stipitate, obovoid to broadly obovoid, 1.2-1.5 mm, flatly biconvex, subsmooth. Fl. and fr. Jun-Aug.
Seashores and sunny wet places at seashores, salty marshes; near sea level. Anhui, Fujian, Guangdong, Hainan, Jiangsu, Shandong, Taiwan, Xisha Qundao, Zhejiang [Japan, Korea].
Fimbristylis sieboldii has often been misidentified as F. ferruginea (Linnaeus) Vahl (e.g., D. A. Simpson & T. Koyama, Fl. Thailand 6(4): 317. 1998) or treated as a variety of F. ferruginea (e.g., Tang & F. T. Wang, Fl. Reipubl. Popularis Sin. 11: 93. 1961). Fimbristylis ferruginea, originally described from Jamaica, differs from F. sieboldii by having ovoid spikelets, broader nutlets, and distribution in the tropics.