Perennial herbs, rarely short-lived or annual, usually rhizomatous or stoloniferous. Leaves usually alternate, all basal or with a few cauline leaves, usually simple, entire or variously toothed, often stem-sheathing; stipules present or absent. Inflorescence usually a terminal raceme or cyme. Flowers actinomorphic or zygomorphic, bisexual or unisexual, usually perigynous, hypanthum free or adnate to ovary; sepals usually 4–6; petals usually 4–6, inconspicuous or well developed, entire or lobed, sometimes absent; stamens usually 5 or 10; anthers basifixed, dehiscing longitudinally or by terminal opening. Ovary inferior to superior, 1–3 locular; ovules numerous; styles free or united basally; stigmas usually capitate. Fruit a dehiscent or indehiscent capsule, sometimes follicle-like; seeds few to numerous.
33 genera with about 500 species, almost cosmopolitan, but concentrated in the Northern Hemisphere; 2 genera and 2 species recorded in Australia.