Herbs, shrubs or trees, sometimes completely scandent or only the branches so. Leaves alternate, variable in size and shape on adventitious growth, normal growth and short shoots; nodes swollen or not, with sheathing ocreae, these ciliate in some genera; petioles arising from base of the ocreae or well above the base. Inflorescence terminal or axillary (in Antigonon terminating in a branched tendril), spicate, racemose, or paniculate, flowers solitary or clustered, perfect, functionally or completely unisexual (if the latter, plant usually completely dioecious), bracteate, borne on short or long pedicels which may be articulated at the middle or below the flower, these with ocreolae. Perianth usually with a hypanthium, the perianth lobes 4—9, imbricate, in 1 or 2 series, equal or the inner or outer series strikingly unequal. Stamens 5—9, filaments free or variously united. Ovary superior, usually trigonous or compressed; styles 2 or 3; stigmas capitate or elongate; ovary 1-celled, ovule 1. Fruit an achene, trigonous or compressed, surrounded by the persistent perianth which may be fleshy or dry, enlarged or not, the perianth lobes in fruit coronate or imbricate, or elongated into wing-like structures, often brightly coloured. Seed 1, embryo with plane cotyledons, these often convolute in a farinous, ruminate or uniform endosperm. Over 800 species in about 32 genera; mostly of temperate distribution primarily in the northern hemisphere.