生活型

herb

形態特徵

• An annual herb, glabrous, erect, 10–50 cm high; main stem terete, branchlets deciduous, subterete, angled when young.
• Leaves simple, alternate, green above, pale beneath, elliptic-oblong or obovate, 5–12 mm long, 3–6 mm broad, papery, round to apiculate at apex, obtuse and equal or nearly so at base, entire; petiole short, 0.3-0.5 mm long; stipules triangular-lanceolate, 0.8–1.5 mm long.
• Flowers axillary; cymules mostly bisexual, the proximal 1 or 2 axils with Staminate flowers, the other axils each with one Staminate flower and one Pistillate flower. Staminate flowers: sepals 5 (4), spreading, white, ovate or elliptic, one-veined, green; stamens 3 (2), filaments united into a column, anthers dehiscing horizontally or obliquely; disc segments 5 (4); pistillode absent; pedicels 0.6–1.3 mm long. Pistillate flowers: sepals 5, spreading, white, ovate-oblong , one-veined, green, acute or apiculate; styles free, bifid; ovary 3-celled, globose, smooth; disc flat, deeply 5-lobed; pedicels 1–2 mm long in fruit.
• Capsules green to brown, depressed-globose, 3-lobed, 1.9–2.5 mm across. Seeds sharply trigonous, 0.9–1 mm long, with 5 or 6 straight parallel ribs on the back.

分布

• 台灣 : Now a circumtropical weed, common throughout the island in Taiwan.
• 世界 : Probably native to America.

引證標本

TAIPEI: Kueishan, Hsu 3452. MIAOLI: Tsaochiao, Ou & Kao 8842. CHANGHUA: Pakuashan, Deng 379. YUNLIN: Huwei, Deng 388. KAOHSIUNG: Ape's hill, Deng 470. PENGHU: Makon, Deng 494. PINGTUNG: Kengting, Kao 4223; Wanluan, Deng 455. TAITUNG: Chihpen, Deng 140; Is. Lanyu, Hsu 9417; Is. Lutao Huang & Kao 6947.

引用文獻

• HUANG, TSENG-CHIENG, Flora of Taiwan, second edition 3: 495. .  (Fl. Taiwan 2nd edit., 台灣植物誌第二版)