生活型

herb

形態特徵

• Annual with purple fibrous roots, tufted in small or rather often relatively large clumps. Culms erect to erect-patent, (10-) 25-60 cm tall, acutely triquetrous with concave sides, 2-5 mm wide, soft, light green.
• Leaves rather many, slightly shorter than culm; blades linear, 2-6 mm wide, folded, light green, soft, gradually tapering to acute apex; sheaths rather long, pale or yellowish brown.
• Corymbs simple or in part compound, occasionally whole inflorescence becomes congested in a globose cluster of spikelets, 2-6 cm wide and as long; rays 3-9, very unequal in length, 1-4 cm long; glomerules of spikelets 5-15 mm across, densely bearing numerous spikelets, dark green or brownish green; leafy bracts 2 or 3, to twice as long as corymb. Spikelets lanceolate to linear-lanceolate, 2-8 mm long, ca. 1 mm wide, 8- to 28-flowered; rachilla not winged.
• Glumes rather laxly disposed, nearly orbicular, rounded at apex, membranaceous, 0.5-0.8 mm long and as wide, faintly 3-nerved, deeply green and tinged with brownpurple on both sides, yellowish on keel. Achenes ovate-elliptic, trigonous, nearly equalling glume, yellow at maturity style ca. 1/2 as long as achene; stigmas 3. Stamens 2 or 1.

分布

• 台灣 : Wet places, often seen in rice fields.
• 世界 : Temperate and subtropical regions of both hemispheres.

引證標本

NANTOU: Chichi, Kao 3918. CHIAYI: Fenchihu, Feung & Kao 261. TAINAN: Chiali, Morimoto 198. TAITUNG: Lanyu Is., Sasaki s. n. May 1924; Chihpen, Koyama 13079.

參考文獻

• KOYAMA, Tetsuo, KUOH, Chang-Sheng & LEONG, Wai-Chao, Flora of Taiwan, second edition 5: 240. 2000.  (Fl. Taiwan 2nd edit., 台灣植物誌第二版)