生活型

herb

形態特徵

• Annual or perennial, terrestrial or amphibious herbs. Stem erect or decumbent, up to 50 cm long, glabrous to minutely glandular.
• Aerial and submerged leaves opposite, sessile, ovate-elliptic to ovate-oblong, to 3 cm long, 1 cm wide, crenate to crenate-dentate, glabrous, pinnately nerved, apex obtuse. Flowers sessile, axillary, solitary or occasionally in terminal or lateral leafy racemes, bi-bracteolate.
• Bracteoles 1.5-3 mm long, linearlanceolate, glabrous, appressed. Calyx 3-5 mm long, glabrous, not striate in fruit; lobes 2.5-3 mm long, narrowly lanceolate. Corolla 6-10 mm long, white throughout or sometimes tinged with pale purple; glabrous outside, villous inside. Stamens 4, posterior filaments 1.5-2 mm long, anterior ones 3-4 mm long, glabrous or slightly villous at base.
• Capsule 4-5 mm long, compressed ovoid-ellipsoid. Seeds dark brown, 0.3-0.45 mm long.

物候

Flowering and fruiting from July to December.

分布

• 台灣 : in southern lowlands. Occurring on damps, ditches and rice fields.
• 世界 : The Ryukyus, Philippine, New Guinea, N Australia, Micronesia and Polynesia.

引證標本

Chiayi City: Tuanchu Neighborhood, 6 Oct 2005, T.-C. Hsu 536 (TAIF); 21 Nov 2008, T.-C. Hsu 1988 (TAIF). Tainan Co.: Guantian Township, Guantian, 22 Feb 2009, T.-C. Hsu 2184 (TAIF); Sinhua Town, Shinhua, 22 Aug 2008, T.-C. Hsu 1603 (TAIF); Guanmiao Township, Guanmiao, 10 Nov 2008, J.-J. Lin 1, 2, 3 (TAIF); 22 Nov 2008, T.-C. Hsu 1995 (TAIF). PALAU. Babeldaob, 14 Sep 1937, T. Hosokawa 9264 (TAI). INDONESIA. Sulawesi (cultivated in Taiwan), 29 Sep 2002, C.-C. Lin 526 (TAIF).

參考文獻

• Tian-Chuan Hsu, Jia-Jung Lin and Shih-Wen Chung, Taiwania 54(4): 403-407. 2009.