Stems twining to 8 m, axillary tubers absent. Leaves: petiole 3–18 mm; blade ovate to elliptic, 2–16 × 0.5–9 cm, base of larger leaves proximal to inflorescence acute to cuneate, apex acute to obtuse. Inflorescences racemes or in branched panicles of racemes, 3–35(–70) cm; single bract subtending each pedicel oblong-oblanceolate, 1–2 × 0.2–0.5 mm; paired bracts subtending each flower deciduous, triangular, 0.6–1 × 0.5–0.8 mm, distinct. Flowers bisexual or functionally unisexual; sepals basally adnate to petals, keeled, becoming winged in fruit, cream-white, elliptic, 1.7–2 × 1–1.3 mm, apex obtuse; petals basally connate, cream-white, elliptic, 1.5–2.3 × 0.8–1.1 mm, apex obtuse, spreading at anthesis; stamens of bisexual and functionally staminate plants fleshy; filaments basally connate and dilated, 2.5–3.8 mm; anthers 0.8–1 mm; stamens of functionally pistillate plants reduced and sterile; pistils in bisexual and functionally pistillate plants 0.4–0.6 mm; styles 0.8–1.5 mm, basally connate 1/3–1/2 their length; stigmas clavate to bifid; pistils of functionally staminate plants reduced; pedicel 1–3 mm. Utricles with style bases persistent, not [rarely] produced in functionally staminate plants, obovoid, 1–1.4 mm.
