Habit and leaf form. Herbs, or herbaceous climbers (or trailing). Annual, or perennial. Leaves cauline (ass.). Plants with neither basal nor terminal concentrations of leaves. Stem internodes solid (ass.). Climbing (or trailing); tendril climbers (usually simple, coiled distally). Tendrils simple. Mesophytic to xerophytic. Leaves alternate; spiral; petiolate; non-sheathing; simple (usually), or compound; palmate (mostly 3–7 lobed). Leaf blades dissected; broadly ovate to orbicular (to subcircular); when simple/dissected, palmately lobed; palmately veined; cross-venulate; cordate. Leaves without stipules (tendrils stipular in position). Leaf blade margins entire (sinuate), or dentate (or lobulate to sinuate-dentate). Leaves without a persistent basal meristem. Leaf anatomy. Hairs present, or absent. Extra-floral nectaries absent.
Reproductive type, pollination. Fertile flowers functionally male and functionally female, or functionally male, or functionally female. Unisexual flowers present. Plants monoecious (usually), or dioecious. Female flowers solitary; with staminodes (3 staminodes), or without staminodes. Male flowers solitary (mostly), or aggregated in ‘inflorescences’; without pistillodes (ass.). Entomophilous.
Inflorescence and flower features. Flowers solitary (mostly both male and female flowers), or aggregated in ‘inflorescences’ (male flowers, rarely); in panicles (male flowers). Inflorescences axillary. Flowers pedicellate; bracteate (male flowers subtended by large broadly-ovate, petal-like bract just below flower at junction or peduncle and pedicel), or ebracteate (female flowers sometimes lacking bract); ebracteolate (ass.); small to large; regular (female flowers solitary); cyclic. Free hypanthium present; campanulate to obconic (in male flowers), or urceolate (in female flowers, the lower part of the floral tube narrowed into a short neck and then expanded upwards into a broadly campanulate upper part); of female flowers adnate to the ovary in the lower part. Perianth with distinct calyx and corolla; 10; 2 -whorled; isomerous. Calyx present; 5; 1 -whorled; shortly gamosepalous; blunt-lobed; imbricate, or open in bud; campanulate; regular. Corolla present; 5; 1 -whorled; polypetalous (AK), or gamopetalous (usually divided to the calyx); more or less valvate; campanulate (broadly), or rotate; regular; white, or yellow. Corolla members entire. Fertile stamens present, or absent. Androecial members definite in number. Androecium 2–3. Androecial members branched and unbranched, or unbranched; adnate (to the hypanthium); all equal (ass.); free of one another; 1 -whorled. Androecium exclusively of fertile stamens. Stamens (2–)3; distinctly dissimilar in shape (unilocular/bilocular); reduced in number relative to the adjacent perianth; oppositisepalous (towards base of hypanthium, on floral tube below petals). Anthers separate from one another (later), or cohering (at first); adnate; dehiscing via longitudinal slits; extrorse; unilocular (1 anther), or bilocular (2 anthers); bisporangiate, or bisporangiate and tetrasporangiate, or tetrasporangiate; appendaged (via the prolonged connective), or unappendaged. Fertile gynoecium present, or absent (from male flowers). Gynoecium 1 carpelled, or 2–5 carpelled. The pistil 1–3 celled. Gynoecium syncarpous; of one carpel, or synovarious, or synstylovarious, or eu-syncarpous; inferior. Ovary unilocular, or plurilocular; 1–3 locular. Gynoecium stylate. Styles 1; partially joined; apical. Stigmas 3; commissural; usually 2 - lobed. Placentation parietal; when the ovary plurilocular, axile. Ovules in the single cavity 20–50; 20–50 per locule (numerous); pendulous, or horizontal, or ascending; non-arillate; anatropous.
Fruit and seed features. Fruit 30–150 mm long; 2–10 cm in diameter; fleshy; spinose, or not spinose; dehiscent, or indehiscent; a berry (a pepo). Capsules when dehiscent, irregularly valvular. Fruit few to many. Seeds non-endospermic; medium sized to large; winged, or wingless. Cotyledons 2 (large, flat). Embryo straight.
Etymology. From the Greek for "to bite"; refers to the bitten appearance of the seeds.