生活型

herb

形態特徵

• Annual herbs. Stems erect, sometimes depressed, 12–50 cm tall, branched or not, more or less minutely pubescent.
• Leaves thin, lower and middle ovate to elliptic, apex obtuse to acute, base obtuse; petiole winged, 1–6 cm long, lyrately lobed, terminal lobe largest, broadly ovate, lateral lobes 1 or 2 pairs, distinct, oblong to obovate, regularly or irregularly crenate-serrate, blade 3–12 cm long, 2–4.5 cm wide, pilose or nearly glabrous on both surfaces.
• Heads 2–3 mm long, 2–3 mm across at anthesis, in terminal or axillary panicles, usually 2 or 3 times branched. Involucral bracts in 1 or 2 series, ca. 1 mm long, oblong to ovate, acute, midrib and central area green, margins thinly fimbriate-scarious, inner bracts somewhat shorter. Receptacle depressed globose. Outer florets many, in 7 or 8 rows, corolla tubular, 0.3–0.5 mm long, whitish to yellowish, style arms exserted. Disc florets ca. 10, corolla funnelform to campanulate, greenish to purplish, deeply 4-lobed at tip, lobes broadly ovate, stamens 4.
• Achenes obovate, compressed, truncate, apex viscid glandular punctate, 1–1.5 mm long, ca. 0.5 mm wide, glabrous, pale brown, ribbed on both sides. Pappus absent or of 2 minute setae on disc florets. Heads 5–8 mm in diam. at maturity.
• Chromosome number, 2n = 18 (Peng & Hsu, 1978).

物候

Fl. Apr-Dec.

分布

• 台灣 : A common weed in Taiwan, especially on clay soils at low to mid elevations.
• 世界 : Tropical and subtropical Asia and Africa.

引證標本

TAIPEI: Shihting, Peng 12877. ILAN: Taipingshan, Peng 7878. TAOYUAN: Yangmei Dairy Station, Peng 3104. NANTOU: Tzuchung, Peng 11423. CHIAYI: Alishan, Hsu 3887. PINGTUNG: Tahanshan, Yang 1228. TAITUNG: Lanyu Is., Peng 10810; Hsiangyang, Peng 11846. HUALIEN: Yenhai Forest Trail, Peng 13002.

引用文獻

• PENG, Ching-I & CHUNG, Kuo-Fang; LI, Hui-Lin, Flora of Taiwan, second edition 4: 933. 1998.  (Fl. Taiwan 2nd edit., 台灣植物誌第二版)