Plants perennial, usually monoecious, sometimes dioecious, climbing; stems annual or perennial, puberulent or glabrous; roots tuberous; tendrils unbranched or 2[–3]-branched. Leaves: blade [subquadrangular] pentagonal, deltate, or ovate, unlobed or 3–5-lobed, lobes broadly triangular or deltate to ovate-deltate, oblong-oblanceolate, or elliptic, margins denticulate or serrulate, surfaces sometimes with disc-shaped glands abaxially near base or bracts filiform or absent. Flowers: hypanthium campanulate; sepals 5, deltate to triangular or linear [ovate-lanceolate, oblong-lanceolate, or linear-subulate]; petals 5, connate 1/2–2/3 length, white, cream, or pale green [orange to yellow], oblong-lanceolate to linear-oblong, 5–10 mm, glabrous or puberulent or tomentose adaxially, corolla rotate to campanulate. Staminate flowers: stamens 3; filaments inserted near hypanthium rim, distinct; thecae distinct or connate, forming a head, sigmoid-replicate, connective narrow; pistillodes with 3-lobed ovary. Pistillate flowers: ovary 3-locular (or 1 or 2 by abortion), globose to ovoid or ellipsoid-cylindric; ovules 1–4(–10) per locule; style 1, narrow; stigmas 1, 3-lobed; staminodes 3, minute. Fruits dry pepos or berrylike, red to scarlet, orange, or golden brown [green], mostly ellipsoid-cylindric [to globose], smooth, glabrous, indehiscent. Seeds [1–]3–12[–30], obovoid, [ovoid or oblong], subcompressed, not arillate, margins variably differentiated, sometimes thinner or with narrow light-colored stripe, surface smooth.
se United States, Mexico, West Indies, Central America, South America.
A discussion of plasticity of inflorescence morphology in Cayaponia was provided by R. McVaugh (2001b)––a flowering branch apparently constitutes a complex branching system, potentially producing solitary flowers, groups of flowers, or new branches from any node. Although these observations pertain directly only to C. attenuata (Hooker & Arnott) Cogniaux, they perhaps also apply to the two species included here.
Species ca. 60 (2 in the flora).
|1||Petioles glabrous; leaf blades hirsute-hispidulous abaxially, pustulate-scabrous adaxially; fruiting peduncles 8–15(–30) mm.||Cayaponia americana|
|1||Petioles usually villous-hirsute, sometimes villous, stipitate-glandular; leaf blades villosulous to hirsutulous; fruiting peduncles 1–4 mm.||Cayaponia quinqueloba|