生活型

herb

形態特徵

• Perennial with long creeping slender rhizomes. Culms remotely or closely arranged in a single row along rhizome, 7-30 cm tall, soft, slender, few-leaved at base.
• Leaves radical and subradical; blades shorter than or occasionally equalling culms, narrowly linear, 2-3 mm wide, soft, herbaceous, scabrid on margins and on abaxial midvein; sheaths membranaceous, brownish or purplish brownish, lower ones almost bladeless.
• Inflorescence a terminal single globose head (rarely consisting of 2 or 3 heads); involucral bracts 3, leaf like, very unequal in length; head globose or broadly ovoid-globose, 5-10 mm long and as wide, pale green and often becoming straw colored at maturity, densely bearing numerous spikelets. Spikelets lanceolate-oblong, compressed, 3-3.5 mm long, jointed at base, 4 or 5-squamose, 1-flowered.
• Glumes ovate-elliptic, folded with an acute keel, membranaceous; pale green, sometimes with resinous spots, 7-nerved including a midvein, cuspidate at apex, keel sparsely spinulose toward apex, projecting beyond glume-apex into a straight or slightly recurved short cusp. Achene 1.5 mm long, obovate, laterally lenticular, brown, punctulate; style 2-cleft.

分布

• 台灣 : Wet soil of both open or shady habitat, also in wet sand near the shore.
• 世界 : Widely distributed as a weed in tropical and subtropical regions of all the world with a number of variants.

引證標本

TAIPEI: Nankan, Kuoh 2220; Shihtin, Kuoh 1241; Shulin, Tanaka 11104; Hsinpeitou, Chuang & Kao 3926; Keelung, Chuang 3937. ILAN: Sulin, Kuoh s. n. Jun 24, 1971; Choutou, Kuoh 2387; Taipingshan, Suzuki s. n. 15 Aug 1928; Luton, Suzuki 3694. NANTOU: Lushan, Hsu & Kuoh 11541; Chitou, Chuang & Kao 3254. KAOHSIUNG: Fengshan, Chuang 4147*. Shihshan, Hsu 13834. PINGTUNG: Shintiliao, Hsu 13227; Ssuchungchi, Hsu 13206. TAITUNG: Lanyu Is., Kuoh 4807, Sasaki s. n. 15 Apr 1907; Chihpen, Koyama et a1 6722.

參考文獻

• KOYAMA, Tetsuo, KUOH, Chang-Sheng & LEONG, Wai-Chao, Flora of Taiwan, second edition 5: 284. 2000.  (Fl. Taiwan 2nd edit.)