生活型

herb

形態特徵

• Tufted annual with fibrous roots only. Culms patent, 8-35 cm tall, relatively out, trigonous, smooth.
• Leaves a few to a culm, basal; blades linear, flat, 1-3 mm wide, shorter than culms, light green; sheaths membranaceous, pale brown, striate.
• Inflorescence umbelliform or congested, 2-10 cm long as wide; involucral bracts 2-4 leaf like, unequal in length, longest one 2 or 3 times as long as inflorescence; rays when present 2-5, patent, 0.8-5 cm long, slightly compressed. Spike bearing 3-10 spikelets on abbreviated axis, oval or somewhat flabelliform, 3 cm long. Spikelets lanceolate-oblong, 10-25 mm long, 2.5-3 mm wide, 15-40-flowered, compressed, greenish and turning straw-colored at full maturity; rachilla non-winged.
• Glumes ovate or broadly so, 3-3.5 mm long, herbaceous or thinly coriaceous; strongly folded with acute keel, 3-nerved on both sides, keel broadly green finely many-veined, apex acute with a straight mucro ca. 0.8 mm long. Achenes 1-1.25 mm long, broadly obovate, trigonous, dark brown, shiny, minutely puncticulate; style elongated, 3-fid, at apex.

分布

• 台灣 : A widespread weed in open grassland, farms and wet sandy riverbanks and shore.
• 世界 : Tropical, subtropical and warm regions of both hemispheres.

引證標本

TAIPEI: Fulung, Kuoh 1700; Nankang, Wang 10861. KAOHSIUNG: Shanping, Kuoh 871. PINGTUNG: Kenting, Kuoh 2149; Ssuchungchi, Hsu 13548. TAITUNG: Lanyu Is., Kuoh 4813.

參考文獻

• KOYAMA, Tetsuo, KUOH, Chang-Sheng & LEONG, Wai-Chao, Flora of Taiwan, second edition 5: 239. 2000.  (Fl. Taiwan 2nd edit.)