The naranjilla plant is a spreading, herbaceous shrub to 8 ft (2.5 m) high with thick stems that become somewhat woody with age; spiny in the wild, spineless in cultivated plants. The alternate leaves are oblong-ovate, to 2 ft (60 cm) long and 18 in (45 cm) wide, soft and woolly. There may be few or many spines on petioles, midrib and lateral veins, above and below, or the leaves may be completely spineless. Young leaves, young stems and petioles are coated with richly purple stellate hairs. Hairs on other parts may appear simple. Borne in short axillary clusters of as many as 10, the fragrant flowers, about 1 1/5 in (3 cm) wide, have 5 petals, white on the upper surface, purple hairy beneath, and 5 prominent yellow stamens. The unopened buds are likewise covered with purple hairs. A brown, hairy coat protects the fruit until it is fully ripe, when the hairs can be easily rubbed off, showing the bright-orange, smooth, leathery, fairly thick peel. The fruit, crowned with the persistent, 5-pointed calyx, is round or round-ovate, to 2 1/2 in (6.25 cm) across and contains 4 compartments separated by membranous partitions and filled with translucent green or yellowish, very juicy, slightly acid to acid, pulp of delicious flavor which has been likened to pineapple-and-lemon. There are numerous pale-buff seeds, thin, flat, hard and 1/8 in (3 mm) in diameter.