Calyx 3-lobed or 3-partite, with the middle lobe usually smaller, sometimes minute or wanting. Corolla: tube short or somewhat elongate, often narrow at the base, broader in the throat; limb subequally or unequally 5-lobed, sometimes partially bilabiate, the two posterior lobes sometimes shorter, and the middle anterior lobe rather longer than the others. Stamens 4, didynamous, inserted in the corolla throat, more or less exserted; filaments filiform; anthers perfectly 1-celled. Ovary 2-celled; style slender, obtuse, slightly clavate or minutely bidentate at the apex. Fruit ovoid, globose or oblong, included within the calyx, often separating into distinct cocci when mature; pericarp slender, crustaceous or equally indurated round the cells, rarely with a pair of spurious cells at their adjacent margins. Seeds short or oblong. Shrubs or undershrubs, often heath-like, dwarf and much branched, sometimes small annual herbs; leaves narrow or small, sometimes minute, alternate, often crowded in axillary fascicles, entire; flowers sessile in the axils of the bracts, arranged in short terminal spikes or heads, which are often aggregated into corymbs or narrow panicles at the summit of the branches; bracts ovate or narrow, more or less imbricate.