Richardia

Annual or perennial herbs. Stipules fused, sheathing, bearing distinct marginal bristles. Leaves opposite, sessile. Inflorescences of compact heads subtended by 2–4(–6) leaf-like bracts. Flowers bisexual. Calyx 4- or 8–lobed; corolla (3-)4–6-lobed, shortly tubular, caducous; stamens alternating with corolla lobes and inserted near apex of tube; style simple, stigma 3- or 4-lobed. Fruit of 3 or 4 one-seeded mericarps.

About 15 species from tropical and subtropical N and S America; 4 species naturalised in Australia.