Shrub: long, decumbent or ascending, smooth, glabrous, often purplish or glaucous branches.

Leaves: long-petioled, orbicular, entire, tipped with a spiny mucro, usually glabrous; stipular spines varying in length, often hooked and strong.

Flower buds: more or less symmetrical. Flowers axillary, solitary, long-pedicelled, showy, white. Sepals glabrous, all more or less equally long, the posterior boat-shaped. Petals obvate-orbicular, almost equal in size, the 2 posterior ones with thickened margins coherent in lower part and forming a nectariferous protuberance. Stamens numerous, with pink or bluish filaments, often shorter than glabrous gynophore.

Berry: 2.5-4 cm., pyriform, dehiscing by valves