Annual or perennial, erect herbs; glabrous or hairy. Leaves opposite; bracts herbaceous. Flowers in paniculate to capitate dichasial cymes, 5-merous, bisexual; epicalyx absent; calyx tubular, cylindric, 15–25-veined, not scarious between veins, 5-lobed; petals exceeding calyx; coronal scales present; stamens 10; ovary 1-celled, with few to many ovules, styles 2, rarely 3. Capsule cylindric to ovoid, opening by 4 (rarely 6) teeth; carpophore short; seeds few to many, reniform, more or less compressed, bluntly tuberculate.
About 30 species, native to temperate Eurasia; 2 species naturalised in Australia.