Herbs with roots often thickened and tuberous, not spiny. Stems ± swollen at nodes. Lvs opposite, petiolate or sessile. Fls ☿, 1-many in ± dense corymbose cymes with very short pedicels; bracts united into a 4-5-lobed calyx-like involucre, sometimes enlarged at fruiting. Perianth most colours except blue; tube elongated, constricted just above ovary; limb spreading, salverform to campanulate. Stamens 3-5-(8), free or connate at base, unequal, = perianth or exserted. Ovary subsessile; style long, filiform; stigma capitate or very shortly lobed, exserted. Anthocarp terete to 5-angled, hard, not viscid, adherent to testa of seed and ± invested in persistent bracts.