Lycium Barbarum
Goji, goji berry, or wolfberry is the fruit of either Lycium barbarum or Lycium chinense, two closely related species of boxthorn in the nightshade family, Solanaceae. L. barbarum and L. chinense fruits are similar but can be distinguished by differences in taste and sugar content.
Lycium barbarum is a deciduous woody shrub, growing 1–3 metres high. The shrub has weak arching branches, and the side branches are often reduced to short leafless spines.
L. barbarum leaves form on the shoot either in an alternating arrangement, or in bundles of up to three. Each leaf is green, scarcely fleshy when fresh, usually lanceolate (spearhead-shaped), sometimes with rounded tips. Clustered leaves are up to 25 mm long; the single alternate leaves are up to 55 mm long.
The flowers grow in groups of one to three in the leaf axils, with pedicels 6–15 mm long. The calyx, eventually ruptured by the growing berry, is a whitish tube crowned by five or six radial triangular sepals, shorter than the tube, 10–12 mm long and 3–4 mm wide, sometimes 2–lipped, strongly curved. The sepals are whitish on the lower side (facing towards the branch) and deep mauve on the top side.
Each flower has five stamens, exserted for 3–8 mm, with stalks longer than the anthers. The pistil is 8–11.5 mm long. The anthers are longitudinally dehiscent.The fruit of L. barbarum, the main variety of goji berry, is a bright orange-red, ellipsoid berry 1–2 cm in diameter. The fruiting calyx is split deeply once or twice. The number of seeds in each berry varies widely based on cultivar and fruit size, ranging from 10 to 60.
The seeds are about 2 mm long, 1 mm wide, yellowish, compressed with a curved embryo.