Habit and leaf form. Lianas. Climbing; stem twiners (the branch tips twining), or scrambling (the branch tips hooked). Stem growth conspicuously sympodial. Leaves alternate; spiral; petiolate; non-sheathing; simple. Lamina entire; pinnately veined; cross-venulate. Leaves stipulate. Stipules caducous (minute). Domatia occurring in the family.
Leaf anatomy. Stomata present; actinocytic. Hairs present; glandular. Complex hairs present; peltate.
Adaxial hypodermis present. Lamina dorsiventral.
Stem anatomy. Cork cambium present; initially deep-seated. Secondary thickening developing from a conventional cambial ring. Xylem with fibre tracheids. Vessel end-walls very oblique; simple.
Reproductive type, pollination. Plants hermaphrodite.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in panicles, in spikes, and in cymes. The ultimate inflorescence unit often apparently cymose (axillary or terminal). Inflorescences spikes, panicles or racemes representing lax or rarely condensed dichotomous cymes. Flowers small; regular to somewhat irregular, or very irregular. The floral irregularity involving the perianth (the calyx becoming very irregular in fruit). Flowers 5 merous; cyclic; tetracyclic.
Perianth with distinct calyx and corolla; 10; 2 whorled; isomerous. Calyx 5; 1 whorled; gamosepalous; unequal but not bilabiate (markedly unequal in the fruit), or regular; persistent; accrescent (forming a winged crown for the floating fruit); imbricate. Corolla 5; 1 whorled; polypetalous, or gamopetalous (at the base). Corolla lobes markedly longer than the tube. Corolla contorted; more or less fleshy.
Androecium 10, or 5 (rarely). Androecial members adnate (to the base of the corolla); markedly unequal (5 somewhat larger), or all equal (when only 5); coherent (at the bases of the filaments); 1 adelphous; 1 whorled. Androecium exclusively of fertile stamens. Stamens 10, or 5; isomerous with the perianth, or diplostemonous; usually both alternating with and opposite the corolla members. Anthers dehiscing via longitudinal slits; introrse, or latrorse. Pollen grains aperturate; 3(–4) aperturate; colporate.
Gynoecium 3 carpelled. Carpels reduced in number relative to the perianth. The pistil 1 celled. Gynoecium syncarpous; synovarious; partly inferior. Ovary 1 locular. Styles 3; free to partially joined. Stigmas 3. Placentation basal. Ovules in the single cavity 1; ascending; non-arillate.
Fruit non-fleshy; indehiscent; a nut. Dispersal unit the nut with its crown of sepals. Dispersal by water. Seeds endospermic. Endosperm ruminate; starchy. Seeds with starch. Cotyledons 2.
Seedling. Germination phanerocotylar.
Physiology, biochemistry. Proanthocyanidins present; cyanidin and delphinidin. Flavonols present; kaempferol, quercetin, and myricetin.
Geography, cytology. Tropical. Tropical Africa to Western Malaysia.
Taxonomy. Subclass Dicotyledonae; Crassinucelli, or Tenuinucelli (?). Dahlgren’s Superorder Theiflorae; Theales. Cronquist’s Subclass Dilleniidae; Violales. APG (1998) Eudicot; core Eudicot; neither Rosid nor Asterid. APG 3 (2009) Order: Caryophyllales.
Species 20. Genera 1; only genus, Ancistrocladus.