Habit and leaf form. Herbs, or herbaceous climbers; laticiferous, or non-laticiferous and without coloured juice. Autotrophic. Perennial; plants with neither basal nor terminal concentrations of leaves. Trailing or climbing; stem twiners. Twining anticlockwise. Helophytic, mesophytic, and xerophytic. Leaves alternate; spiral; petiolate; non-sheathing; simple. Leaf blades entire; pinnately veined, or palmately veined; cross-venulate; hastate, or sagittate. Leaves without stipules; without a persistent basal meristem. Stem anatomy. Nodes unilacunar. Secondary thickening anomalous, or developing from a conventional cambial ring; via concentric cambia, or from a single cambial ring.
Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite.
Inflorescence and flower features. Flowers solitary (usually), or aggregated in ‘inflorescences’; when solitary, axillary; in cymes. The terminal inflorescence unit cymose. Inflorescences axillary; with involucral bracts, or without involucral bracts. Flowers bracteate; bracteolate. Bracteoles usually large and enclosing the calyx. Flowers medium-sized, or large; regular to somewhat irregular. The floral asymmetry (when noticeable) involving the perianth (K only). Flowers 5 merous; cyclic; tetracyclic. Free hypanthium absent. Hypogynous disk present; annular. Perianth with distinct calyx and corolla; 10; 2 -whorled; isomerous. Calyx 5; 1 -whorled; polysepalous; imbricate; regular to unequal but not bilabiate (subequal); persistent; with the median member posterior. Corolla 5; 1 -whorled; gamopetalous; slightly lobed, or entire; campanulate, or funnel-shaped; regular; glabrous abaxially; glabrous adaxially; white, or white and pink (tinged). Androecium 5. Androecial members adnate (to the corolla); all equal to markedly unequal (actually subequal); free of one another; 1 -whorled. Androecium exclusively of fertile stamens. Stamens 5; remaining included; oppositisepalous. Anthers dehiscing via longitudinal slits; introrse; tetrasporangiate. Pollen grains psilate. Gynoecium 2 carpelled. The pistil 1 celled (the septum incomplete). Gynoecium syncarpous; synstylovarious; superior. Ovary unilocular; 1 locular. Gynoecium median. Styles 1; simple; apical. Stigmas 2 (the stigmatic area and style distinct); 1 - lobed; dry type; papillate; Group II type. Ovules in the single cavity 4; ascending; apotropous; non-arillate; anatropous.
Fruit and seed features. Fruit non-fleshy; not hairy; dehiscent; a capsule. Capsules loculicidal (via 4 valves). Fruit 1 locular; 4 seeded. Seeds endospermic. Endosperm oily. Seeds not conspicuously hairy. Cotyledons 2. Embryo chlorophyllous; straight, or curved. Seedling. Germination phanerocotylar.
Physiology, biochemistry. Aluminium accumulation not found. Photosynthetic pathway: C3.
Geography, cytology, number of species. Native of Australia. Not endemic to Australia. Australian states and territories: Western Australia, South Australia, New South Wales, Victoria, Australian Capital Territory, and Tasmania.
Additional characters Pollen grains porate. Stigmas the stigmatic area oblong or elliptic.