Smilax aspera is a perennial evergreen shrub with a flexible and delicate stem, with sharp thorns. The climbing stem is 1–4 metres (3 ft 3 in–13 ft 1 in) long.The leaves are 8–10 centimetres (3.1–3.9 in) long,petiolated, alternate, tough and leathery, heart-shaped, with toothed and spiny margins. Also the midrib of the underside of the leaves are provided with spines. The flowers, very fragrant, are small, yellowish or greenish, gathered in axillary racemes. The flowering period in Mediterranean regions extends from September to November. The fruits are globose berries, gathered in clusters, which ripen in Autumn. They are initially red, later turn black. They have a diameter of 8–10 millimetres (0.31–0.39 in)and contain one to three tiny and round seeds. Insipid and unpalatable to humans, they are a source of nourishment for many species of birds.