Perennial herbs; stems prostrate to erect, non-twining; leaves small, sessile or nearly so, broadly ovate to linear, entire; inflorescences axillary, mostly 1-flowered; calyx of 5 free sepals; corolla of 5 united petals, rotate or shallowly funnelform, white or pale blue; stamens 5; pistil 1, with 2 carpels, each style deeply 2-cleft (thus appearing 4-stylar); fruit a 4-valved, 4-seeded capsule.