Herbaceous creeper or climber to 5 m., perennial, essentially glabrous throughout; stem terete. Leaf-blades 3-lobed to about half-way, suborbicular in outline, 4–10 by 4–11 cm., base rounded, truncate or cordate, subpeltate, (3–)5-nerved from base, herbaceous; lobes elliptic to oblong, up to 5 cm., top obtuse or acutish, ± 1 mm. mucronate; margin entire except for a few gland-teeth in or near the lobe-sinuses; petiole 3–6 cm. Glands on petiole 2–5, scattered or ± paired at about the middle, slender, up to 1 mm. long; blade-glands absent. Stipules ovate-oblong, straight, 1.5–4 cm. long, entire or with a few minute gland-teeth, top mucronulate. Inflorescences 1-flowered, the straight peduncle 3–6 cm., inserted beside a simple tendril 4–12 cm.; bracts and bracteoles ovate or broadly ovate, 1–1.5 cm., acute, entire or with a few minute gland-teeth at base, forming an involucre. Flowers 4–5.5 cm. in diameter, white. Hypanthium broadly cup-shaped, 7–10 mm. wide; sepals oblong, 2–2.5 cm., obtuse, with a subapical horn 0.5–1 cm. Petals oblong, 1.5–2 cm., acutish. Corona composed of 4 or 5 series of threads, those of the outer 2 series 1(–1.5) cm. long, those of inner series 2–6 mm.; operculum subplicate, fimbriate-laciniate for about half or less, and with a fringe of inward curved dentiform processes; disk annular; limen with lobulate edge, erect or ± reflexed at the top, closely surrounding the androgynophore. Androgynophore 10–12 mm.; filaments 5–6 mm., dilated; anthers 5–7 mm. Ovary ellipsoid, ± 4 mm., glabrous; styles 8–10 mm. Fruit ± leathery, ellipsoid or subglobose, excluding the 1.5–2 cm. long gynophore 3.5–4.5 cm. long, greenish turning yellow. Seeds many, ellipsoid, 4–5 mm. Fig. 4, p. 17.