生活型

herb

形態特徵

• Rhizome suberect or hardly developing; roots thickish. Culm as a rule solitary, rarely 2 or 3 together, 30-90 cm tall, triquetrous, coarse, rigid, scabrid on upper angles.
• Leaves more or less equalling culm; blades broadly linear, 5-12 mm wide, stiffish, flattish plicate, scabrous on margins; sheaths light brown.
• Corymbs hemispherical, 7-15 cm across, 5-8 cm high, subdense, compound to decompound; rays many (-17), rather slender, 2-8 cm long, smooth, spicately bearing 4 to 16 raylets that are 1-3 cm long; leafy bracts 4-12, surpassing corymb, lower few to 60 cm long; bracteoles setaceous. Spikelets digitate in groups of 2-7 at apices of raylets, each lanceolate-oblong, flattened, 5-8 mm long, ca. 2.5 mm wide, densely 15-50-flowered, straw colored, stained with brown or rusty-brown.
• Glumes broadly ovate, 2-2.5 mm long, thickly membranaceous to herbaceous, suddenly contracted from above base to mucronate apex, greenish keel broad, inconspicuously 3-nerved. Achenes 2/3 to 3/4 as long as glume, oblong-elliptic or oblong-ovate, trigonous with concave sides, glaucous-brownish angles markedly spongy-thickened, pale brown; style flattened, slightly shorter than achene, pilose; stigmas 3, short. Stamens 3.

分布

• 台灣 : Growing in large floating communities in pond or lakes.
• 世界 : India, Malesia, northern Australia.

引證標本

NANTOU: Sun Moon Lake, Kitamura 1346, Kudo & Sasaki 15376, De Vol 7506*. PINGTUNG: Suchongchi, Kuoh 13213.

參考文獻

• KOYAMA, Tetsuo, KUOH, Chang-Sheng & LEONG, Wai-Chao, Flora of Taiwan, second edition 5: 248. 2000.  (Fl. Taiwan 2nd edit.)