Lycium are shrubs, often thorny, growing 1 to 4 meters tall. The leaves are small, narrow, and fleshy, and are alternately arranged, sometimes in fascicles. Flowers are solitary or borne in clusters. The funnel-shaped or bell-shaped corolla is white, green, or purple in color. The fruit is a two-chambered, usually fleshy and juicy berry which can be red, orange, yellow, or black. It may have few seeds or many. Most Lycium have fleshy, red berries with over 10 seeds, but a few American taxa have hard fruits with two seeds.
While most Lycium are monoecious, producing bisexual flowers with functional male and female parts, some species are gynodioecious, with some individuals bearing bisexual flowers and some producing functionally female flowers.