南美蟛蜞菊 nan mei peng qi ju

Silphium trilobatum Linnaeus, Syst. Nat., ed. 10, 2: 1233. 1759; Thelechitonia trilobata (Linnaeus) H. Robinson & Cuatrecasas; Wedelia trilobata (Linnaeus) Hitchcock.

Herbs, perennial, procumbent. Stems stout, glabrous or pubescent, seldom scabrid. Leaves opposite, somewhat succulent; petiole distinct but less than 5 mm; blade elliptic or lanceolate, to 18 cm, often with triangular lobes and conspicuous marginal teeth, glabrous or sparsely pubescent, sometimes scabrid, base cuneate, apex acute. Capitula solitary on elongate peduncle, radiate; involucre green; phyllaries lanceolate, 10-15 mm, ciliate, obscurely veined, innermost narrower. Ray florets 4-8, showy, yellow, 15-20 mm, 3- or 4-denticulate, fertile. Disk florets numerous, yellow, ca. 2 cm; corolla 5-6 mm. Achenes blackish, sometimes mottled, clavate, angled, ca. 5 mm; pappus of fused scales, coroniform.

Cultivated as an ornamental ground cover and escaped in many countries, occasionally naturalized on slopes and along roadsides at lower elevations. Guangdong, Taiwan [native to the New World tropics but widespread in the Old World tropics].