金钮扣 jin niu kou

Spilanthes paniculata Wallich ex Candolle, Prodr. 5: 625. 1836; S. acmella (Linnaeus) Murray var. paniculata (Wallich ex Candolle) C. B. Clarke ex J. D. Hooker.

Herbs, annual. Stems branched, erect or ascending, to 30 cm or more tall, rarely rooting at nodes. Petiole 1-2 cm; leaf blade ovate to ovate-lanceolate, 2-4 × 1-2.5 cm, 3-veined, base cuneate, margin entire or coarsely or crenately serrate, apex acute. Capitula discoid, solitary, terminal or axillary, 8.4-12.5 × 6.9-10 mm; peduncles 2.5-16 cm, sparsely pilose; phyllaries 9-12, 2-seriate, ovate-lanceolate, ca. 6 mm, herbaceous, glabrous; receptacle 5-8 × 1.1-3 mm, apex acuminate. Florets 90-200; corollas tubular, minute, 4- or 5-lobed. Achenes obovoid, 3-angled, ca. 3 mm, margin scabrid, apex slightly depressed; pappus of 2 subequal bristles, longer one 0.5-1.1 mm, shorter one 0.4-0.9 mm. Fl. Apr-Nov. 2n = 26.

Fields, wastelands, roadsides, forest margins; 800-1900 m. Guangdong, Guangxi, Taiwan, Yunnan [India, Indonesia, Laos, Malaysia, Myanmar, Nepal, Philippines, Sri Lanka, Thailand, Vietnam].