生活型

herb

形態特徵

• Branched annuals, 20–70 cm tall, stems sparingly pilose basally, branchlets and peduncle densely strigose and pilose, often with intermixed red glandular capitate hairs.
• Petiole 3–7 mm long. Leaves ovate to lanceolate, coarsely toothed, 2.5–7×1.2–5 cm.
• Heads numerous, pedunculate; involucral bracts sparsely capitate glandular, unequal, in two series, outer bracts ca. 2×1 mm, inner bracts ca. 3.8–4×2 mm, margins scarious, entire to minutely laciniate. Ray florets 5 (rarely 4 or 8); ligules obovate to quadrangular, ca. 0.8–0.9×0.5 mm; tube 0.8–0.9 mm long, densely patently hairy; achenes black, 1.3–1.8 mm long, strigillose; pappus scales 10–20, elliptic to obovate, often aristate, fimbriate, white to brownish, to 1.5 mm long. Disc corollas yellow, 0.8×0.4 mm long.
• achenes black, obconical, 4 or 5 angled, 1.3×5 mm, brownish strigillose; pappus scales ca. 20, buff, oblanceolate, 0.9–1.5×0.2–0.3 mm long. Paleae narrowly oblong lanceolate, ca. 2.5 mm long, entire to irregularly and shallowly trifid.

分布

• 台灣 : naturalized in the northern and central parts of the island along roadsides, in cultivated fields and at borders of disturbed forests and plantations, 200–1,300 m.
• 世界 : Native of tropical America, now a cosmopolitan weed.

引證標本

TAIPEI: Yangmingshan National Park, Chutzuhu, Liu 229; Pingtengli, Peng 11344. HSINCHU: Shihtoushan, Peng 14849. NANTOU: Chitou, Chiu 3140.

參考文獻

• PENG, Ching-I, CHUNG, Kuo-Fang & LI, Hui-Lin, Flora of Taiwan, second edition 4: 968. 1998.  (Fl. Taiwan 2nd edit.)