美形金钮扣 mei xing jin niu kou

Spilanthes calva Candolle in Wight, Contr. Bot. India, 19. 1834; S. acmella (Linnaeus) Murray var. calva (Candolle) C. B. Clarke ex J. D. Hooker; S. callimorpha A. H. Moore.

Herbs, perennial. Stems creeping or prostrate, 20-60 cm, glabrous, rooting at nodes, sparsely pilose. Petiole 5-8(-24) mm, pubescent; leaf blade lanceolate, 3-7 × 1-3 cm, abaxially subglabrous or only pubescent along veins, adaxially pubescent, base cuneate, margin peaked serrate, apex acuminate or caudate. Capitula ovoid-conical, 9-11(-14) × 6-8 mm; peduncles 3-14 cm; phyllaries ca. 8, 2-seriate, subequal, green, ovate-oblong, 3-3.5 mm, margin ciliate, apex acute or obtuse; receptacle columnar-conical, 4-8 mm; paleae oblong, navicular, membranous. Corollas yellow; ray florets female, ca. 4 mm, lamina short, obovate, apex shallowly 3-lobed; disk florets bisexual, tubular, ca. 2 mm, 4- or 5-toothed. Achenes brown, oblong, 1.5-2 mm, pubescent or glabrous; pappus 2, arista-like. Fl. May-Dec (often flowering year-round).

Streamsides, marshes, moist forest margins, fields; 1000-1900 m. Yunnan [India, Indonesia, Myanmar, Nepal, Philippines, Sri Lanka, Thailand].