生活型

herb

形態特徵

• Annual, prostrate or ascending branch 1-30 cm long, pube rulent in 2- rows .
• Le av e s lin e a r to na r rowly oblanceolate, 10-30 mm long, 1.5-7 mm wide, lower margins fringed with cilia and setae, adaxial surface glabrous, abaxial densely ciliate and dotted with round oil-glands, 0.1-0.3 mm in diam., setae 4-8 pairs, 1-3 mm.
• Heads solitary or 2-3 aggregated, with leafy cymiform arrays. Peduncles 1-2 mm, bracts 4, narrowly ovate, apex acuminate, margin ciliate, 2.5-4 mm long. Involucres campanulate, cylindric, ellipsoid or obovoid. Involucral bracts 5 or 6 in 1 row, oblong to obovate, coriaceous, glabrous, 1-ridged, 5-7 mm long, 1-3 mm wide, apex trun cate and emarg in ate, upper part constricted. Ray florets 5, pistillate; pappi (scales) 2, corollas yellowish, 3.5-4 mm long, apex emarginate. Disc florets 10 - 18, bisexual; pappi 5, corollas yellowish, ca. 3 mm, 4-lobed; anthers apex acuminate into an acute tip, base obtuse, ca. 0.7 mm long; pistil 1, style coated with prickle, style branch ca. 0.5 mm long.
• Achenes oblanceolate, blackish when mature, surface tuberculate, ca. 3.5 mm, 2 ridged, coated with 2-4 rows of hairs at margin, upper part pubescent, hairs to 0.75 mm long; pappi lanceolate, membranous, margins sparsely serrate, 1.5-2.5 mm long.

分布

• 台灣 : In southern Taiwan, this plant has been well-established and naturalized at grasslands and riverbanks along the Kaoping River. Our botanical surveys revealed ca. 400 individuals in three subpopulations at this locality.
• 世界 : native to tropical America, i.e. SE America, Mexico, West Indies and Central America.

引證標本

Kaohsiung County, Linyuan Township, Linyuan Riverside Park, 16 July 2007, Yui-Ching Kao s. n. (TAIF), Riverside of Kaoping River, near Shuan-Yuan Bridge, 8 October 2010, Chun-Wan Hsien s. n. (TNU), same loc., 8 October 2010, Ming-Jer Jung 5121 (TNU).

參考文獻

• Ming-Jer Jung, Chun-Wan Hsien, Yui-Ching Kao and Ching-Long Yeh, Taiwania 56(2): 173-176. 2011.