Richardsonia Kunth: 43 (1818).
Annual or perennial herbs, hairy; stems erect or prostrate. Leaves sessile or shortly petiolate, usually ovate, lateral nerves evident; stipule sheath connate with petioles, bearing several fimbriae. Flowers in dense, terminal heads, surrounded by an involucre of leaves which are several-nerved from base. Calyx 4-8-lobed; lobes lanceolate, ovate or subulate, persistent; tube turbinate or subglobose. Corolla 3-5-lobed, white; lobes ovate or lanceolate; tube shortly funnel-shaped. Stamens 3-5, arising in corolla throat; filaments filiform; anthers linear or oblong, exserted. Ovary 3- or 4-locular with a solitary erect ovule in each locule attached near middle of septum; style filiform, exserted; stigmas 3 or 4, linear or spathulate. Fruit a capsule, separating into cocci, crowned with persistent calyx; cocci muricate or papillose, rarely smooth. Seeds oblong-ellipsoid or obovoid, convex on back. x = 7 (8) (1 report, polyploidy).
Species 15, tropical America; 4 naturalised in eastern regions of sthn Afr., absent from Namibia, Botswana, Northern and Western Cape.