Shrubs with rigid, prickly, cylindrical branches. Leaves opposite, rarely 3, rigid, small; stipules connate with petiole to form an entire sheath with 2 bristles, floral stipules dissimilar. Inflorescence cymose. Flowers small, white or pink. Calyx-tube ovoid; lobes 5, not accrescent after anthesis, dialated into feathery bristles. Corolla infundibuliform, puberulous outside, 5-partite. Stamens ± exserted.