Robust prickly low-growing diffusely branched shrub; stems armed with broad-based, straight or downward-pointing prickles and clothed in a mixture of stellate and simple glandular or nonglandular hairs (viscid-pubescent). Leaves alternate, simple, clearly petioled (these also prickly); blades oval-triangular, nearly as broad as long, to 20 cm (8 in) long and 15 cm (6 in) wide, angular-lobed; surfaces dense with fine soft hairs giving blades a velvety sheen (hairs a mix of types as on stems); veins prickly. Flowers white, in small terminal clusters; 5 petals white, recurved; stamens with prominent cream-colored anthers. Fruit a globose berry, 2-3 cm (0.8-1.2 in) wide, green with dark veining, like a tiny watermelon, when immature, dull medium yellow when ripe; seeds about 400 per berry.

Counteracts hyperactivity due to amphetamines, stimulates the central nervous system and alleviates spasms (plant).