Description from Flora of China
Herbs, annual or perennial. Leaves opposite or alternate in upper part, petiolate, margin serrate. Capitula small, terminal or axillary, slender and long pedunculate; involucre ovoid, ovoid-campanulate, or hemispheric; phyllaries few, outer papery; receptacle convex; paleae rigid and dry membranous. Ray florets female, 1- or 2-seriate, lamina light yellow, yellow, or rarely white, short or very short, apex 2-4-dentate. Disk florets tubular, limbs 5-dentate. Anther tails obtuse, entire or inconspicuously auriculate. Achenes glabrous or pubescent, apex truncate, of female florets 3-ribbed, dorsally compressed, of bisexual florets 3- or 4-ribbed, or laterally compressed; pappus 2-5, unequal, spinelike or squamalike, base connate.
About ten species: tropics; one species in China.