生活型

herb

形態特徵

• Erect annuals; stems 30–100 cm tall, branched, soft pubescent.
• Leaves 3–11 cm long, bi- or tri-pinnatifid, upper surface slightly pubescent, lower surface pubescent.
• Racemes terminal, slender, staminate heads above, nodding; pistillate heads few, on lower part or raceme; involucre bracts connate, pubescent, glandular.
• Involucre and achenes united into a hard false fruit with wart-like papillae.

分布

• 台灣 : a widely naturalized weed along freeways, open construction sites and waste places in lowlands.
• 世界 : Native of North America; a polymorphic weed widely naturalized in the warmer parts of the world.

引證標本

TAIPEI: Shihmen, Ho 291. HSINCHU: Chupei, Hsinkang Village, Peng 15231; Lienhuassu, Kao106. NANTOU: Wushe, Peng 2309.

參考文獻

• PENG, Ching-I & CHUNG, Kuo-Fang; LI, Hui-Lin, Flora of Taiwan, second edition 4: 826. 1998.  (Fl. Taiwan 2nd edit.)