生活型

herb

形態特徵

• Perennial with reddish purple fibrous roots; rhizomes slender, horizontal, short elongated. Culms solitary and arranged in a row along elongated rhizome, or tufted with a short rhizome, erect, mostly 10-50 cm tall, slender, trigonous, rather soft.
• Leaves as a rule reduced to bladeless sheaths at base of culms; sheaths 2-10 cm long, pale-green and usually tinged with brown, purple-brown or red-purple; blades occasionally developing especially in relatively dry habitats, short.
• Corymbs compound or simple, rather lax, 8-15 cm long and as wide; rays several, unequal, longer ones 5-10 cm long, slender, raylets; if developing, few-2 cm long; leafy bracts 1 or 2, longer one equalling to slightly shorter than corymb. Spikelets digitately disposed at apices of ray or raylet in 4 to 6, linear-oblong, obtuse-tipped, flattened, 5-15 mm long, 1-1.5 mm wide, subdensely 10- to 28-flowered, wingless rachilla is completely hidden by densely disposed glumes.
• Glumes elliptic to lanceolate-elliptic, ovate, ca. 1.5 mm long, membranaceous, pale-brownish and often tinged or variegated with rusty-brown or purplebrown, slenderly 3-nerved, greenish keel ending in a short mucro at straight apex. Achenes obovate, trigonous, 0.5 mm long, cream-yellow, tuberculate; style 1.5 times as long as achene; stigmas 3. Stamens 3-1.

分布

• 台灣 : Common in wet places, often becoming a weed in rice fields.
• 世界 : Temperate, subtropical and tropical regions of all the world.

引證標本

TAIPEI: Tatungshan, Sasaki s. n. 26 Aug 1928; Fulong, Hsu s. n. 25 Sep 1960; Kueishan, Chuang 3102; Yangminshan, Yamamoto s. n. Aug. 1929; Wantan, Simizu 2449; Shulin, Tanaka 11106; Muchushan, Suzuki 12034. TAOYUAN: Tantsuchiau, Sasaki s. n. 18 Nov 1933. NANTOU: Sueshe Lake, Kudo & Sasaki 15052. TAITUNG: Lanyu Is. Sasaki s. n. 7 Nov 1934.

參考文獻

• KOYAMA, Tetsuo, KUOH, Chang-Sheng & LEONG, Wai-Chao. 2000. Flora of Taiwan, second edition 5: 244. (Fl. Taiwan 2nd edit.)