Fls axillary, us. in terminal racemes or spikes, sts solitary. Calyx campanulate, 4-lobed, clefts even or uneven. Corolla-tube funnelform, short or much-elongated, ± pilose without; limb 2-lipped, upper lip concave, shortly 2-lobed, lower lip 3-lobed, spreading. Stamens 4, didynamous, inserted at throat of corolla; anthers cohering by margins, us. carried laterally by curvature of filaments, rarely free and erect, cells us. marginally hairy, equally or unequally awned at base. Style slender, stigma ± clavate to capitate, sts imperfectly 2-lobed. Fr. a loculicidal laterally compressed capsule, rarely indehiscent; seeds 1-(, testa whitish and furrowed. Annual to perennial semi-parasitic herbs or subshrubs with opp. lvs. Genus of c. 100 spp. widespread in temperate regions of both hemi-spheres, the N.Z. spp. endemic.

Annual or perennial semi-parasitic herbs; stems either erect and sometimes woody at base, or slender and prostrate and then often rooting at the nodes. Lower and upper lvs similar or dissimilar, opposite or upper subopposite, usually toothed, sometimes glandular. Fls usually in bracteate, terminal spikes or racemes, sometimes solitary in the axils of leaflike bracts. Calyx tubular or campanulate, with 4 equal lobes and equal or unequal clefts between. Corolla tube short or long, funnelform; limb 2-lipped; upper lip hooded or grooved, ± 2-lobed; lower lip with 3, usually emarginate lobes. Stamens 4, equal or unequal; anthers awned at base; cells parallel. Fr. a loculicidal capsule, laterally compressed. Seeds numerous, usually oblong or fusiform, furrowed, very small; wing 0.