Perennial; stems prostrate, to 3 m., sparsely setulose, rooting at nodes, arising from tuberous roots up to 1 m. below ground. Leaf-lamina 6·5–12·5 × 3·5–10 cm., ovate or ovate-oblong in outline, finely setulose or hispid above and more densely so beneath, becoming scabrid, deeply palmately (3)5(7)-lobed, lobes elliptic, narrowly oblong-elliptic or lanceolate, obtuse to acute, apiculate, sinuate-dentate or sinuate-lobulate, the central much the largest. Petioles 1–5 cm. long, aculeate-setulose, becoming scabrid. Flowers dioecious. male flowers solitary or 2–3 in small fascicles; pedicels 8–10(20) mm. long. Receptacle-tube 5–7 mm. long; lobes 2·5–5 mm. long. Petals 5·5–10 mm. long, yellow. female flowers solitary; pedicels (4)8–10 mm. long; ovary c. 13 × 5 mm., ellipsoid, densely setose; perianth rather larger than in male flowers, otherwise similar. Fruit 3–5·5 × 2–3 cm., oblong or oblong-ellipsoid, rounded at the ends, densely shortly softly spiny, green or greenish-white, longitudinally variegated with brownish-purple; spines 2–5 mm. long, laterally compressed, rather thick; fruit-stalk stout, c. 2 cm. long, slightly expanded upwards. Seeds 6–7 × 3–4 × 1·5–2 mm., elliptic in outline, smooth, pallid, subcompressed.
