Dioecious prickly scrambling perennial up to 3m. Leaves occur in whorls of 6-8, ovate-lanceolate, margins very prickly; flowers in axillary cymes, flower stalks very woolly. At pollination each flower sends out a long woolly thread with the seed attached to the tip of each thread. Birds use the woolly threads to line their nests thus helping to disperse the seed.