Acmella  

Herbs, annual or perennial. Leaves opposite and/or basally rosulate. Capitula solitary or in few-headed cymes, radiate, disciform, or discoid. Involucres ± hemispheric to ovoid; phyllaries 1-3-seriate, subequal or with outer row spreading and longer, entire or irregularly dentate; receptacles conical; paleae falling with achene, ± navicular, membranous to scarious, each ± equaling subtended floret. Ray florets, when present, 2- or 3-lobed, variously colored. Disk florets: corolla yellow or orange, 4- or 5-lobed. Achene margin ciliate, glabrous, or sometimes corky; ray achenes broadly ovate or elliptic, 3-angled; disk achenes ellipsoid, strongly compressed; pappus absent or of up to 10 awnlike bristles. x = 13.