Description from Flora of China
Herbs, annual to perennial. Stems with resin canals, but without fibers in phloem. Leaves dentate, long decurrent, hairy, sessile or petiolate. Capitula heterogamous, disciform, few to many, terminal in large open leafy panicles. Involucre campanulate; phyllaries 4-8-seriate, imbricate, narrow, usually squarrose. Receptacle naked. Marginal florets female, corolla filiform, 3-lobed; disk florets bisexual, few, tubular. Corolla pink or mauve. Anthers with sagittate bases, without tails; cells of antheropodium flattened; endothecial tissue radical. Style branches with obtuse sweeping hairs reaching below furcation. Achenes oblong-ellipsoid, without resin ducts, sparsely hairy with straight hairs. Pappus of free, barbellate, capillary bristles in 1 row; each bristle with adpressed teeth. x = 10.
The two species in China are often synonymized. If treated as separate species, the correct name for the species Laggera pterodonta is L. crispata, based on Conyza crispata Vahl (1790), which antedates Candolle’s name Blumea pterodonta from 1834.
About 17 species: tropical Africa, Arabia, and Asia; two species in China.