生活型

herb

形態特徵

• Perennial coarse herbs to 2 m tall; stems terete, striate, crisp-puberulous.
• Leaves opposite, median ones larger, ovate to subdelotoid, 7–15×3.5–8 cm, apex acute to acuminate, base obtuse to very broadly cuneate or truncate, sometimes decurrent, lower surface glandular punctate, 3-nerved, margins sparsely dentate, sometimes entire apically, petiole 1–2.5 cm long; upper leaves gradually smaller near inflorescence.
• Inflorescence loose corymbs, heads ca. 10 mm long, 4.5–5 mm wide, peduncle 8–16 mm long, densely pubescent; involucre cylindric, ca. 7 mm long; bracts ca. 30, 3–4 seriate, trinerved, outer ones ovate to ovate oblong, inner ones narrowly oblong, apex acute, base obtuse, sparsely pubescent. Florets ca. 30.
• Achenes black, ca. 4–4.5 mm long, 5-angular, pubescent on ribs.

分布

• 台灣 : introduced as a medicinal herb and naturalized in the south.
• 世界 : Native of tropical America, escaped and naturalized in Asia.

引證標本

KAOHSIUNG: Wanshoushan, Leu 956. PINGTUNG: Liangshan, Peng 13641.

引用文獻

• PENG, Ching-I & CHUNG, Kuo-Fang; LI, Hui-Lin, Flora of Taiwan, second edition 4: 901. 1998.  (Fl. Taiwan 2nd edit., 台灣植物誌第二版)