Annual or perennial herbs, shrubs, or leafless parasites, often with climbing or trailing stems, sometimes erect, rarely small trees, glabrous or pubescent, milky sap often present. Leaves alternate, simple, entire to deeply lobed; stipules absent. Inflorescences usually axillary cymes, sometimes reduced to a single flower; bracteoles usually present. Flowers regular, rarely slightly zygomorphic, bisexual; sepals usually 5 (rarely 3, 4 or 6), usually free; corolla campanulate, tubular or funnel-shaped, rarely rotate or trumpet-shaped, usually 5-lobed (rarely 3-, 4- or 6-lobed); stamens 5, fused to base of corolla-tube, alternating with the corolla-lobes; anthers 2-celled, dehiscing by longitudinal slits; disc usually present, ring- or cup-shaped; ovary superior, usually 1- or 2-celled, rarely 3- or 4-celled, ovules usually 2 (rarely 1) per cell, styles 1 or 2, entire or forked; stigmas variously shaped. Fruit usually a capsule, dehiscing by valves, rarely a berry or indehiscent; seeds usually 4 or 6, sometimes less by abortion, usually with little endosperm.
About 55 genera with about 1650 species, virtually cosmopolitan but mainly in tropical and subtropical regions; 20 genera and c. 130 species in Australia.
Included in the family are a number of species with edible starchy tubers, such as the important crop plant Ipomoea batatas Lam. (Sweet Potato) and several native species of Ipomoea that were eaten extensively by aborigines. Some exotic species of Ipomoea (Morning Glories) are widely cultivated for their showy flowers.
The family Cuscutaceae is sometimes recognised as a separate family from Convolvulaceae.