Climbers or sometimes erect herbs, mostly provided with axillary tendrils (tribe Passifloreae), or erect shrubs or trees (tribe Paropsieae), glabrous or hairy, rarely thorny. Leaves mostly alternate, simple or compound, entire or lobed, often with glands on petiole and blade; stipules small, sometimes caducous. Inflorescences axillary, either cymose (Passifloreae), ending in 1–several tendrils or not, or racemose (Paropsieae); bracts and bracteoles usually small. Flowers hermaphrodite or functionally unisexual (then plants often dioecious or polygamous); stipe articulate to pedicel; hypanthium saucer-shaped to tubiform. Sepals 4–5(–6), imbricate, free or partially connate (Adenia in part), often persistent. Petals (3–)4–5(–6), imbricate, rarely absent. Corona extrastaminal, inserted on the hypanthium, various, composed of hairs, or of 1 or more whorls of thread-like processes or scales, or tubiform or cup-shaped, or absent (Adenia in part). Disk mostly extrastaminal, annular or composed of 5 mostly strap-shaped parts (Adenia), or absent. Stamens 4-many, inserted on the hypanthium or on an androgynophore, if few alternipetalous, free or partially connate; anthers 2-thecous, basifixed to dorsifixed, versatile or not, sometimes apiculate, opening lengthwise. Ovary superior, sessile or on a gynophore or androgynophore, 1-locular, 3–5(–6)-carpellate, with 3–5(–6) parietal placentas; ovules mostly numerous, anatropous; styles 1 or 3–5, very short to distinct, free or partially united; stigma capitate to subglobose, sometimes much divided (Adenia). Fruit a loculicidally 3–5-valved capsule, or berry-like. Seeds mostly compressed, enveloped by a membranous or mostly pulpy aril; funicles often distinct; testa crustaceous, mostly pitted; endosperm horny; embryo large, straight, with foliaceous cotyledons.