Ziziphus /ˈzɪzɨfəs/ is a genus of about 40 species of spiny shrubs and small trees in the buckthorn family, Rhamnaceae, distributed in the warm-temperate and subtropical regions throughout the world. The leaves are alternate, entire, with three prominent basal veins, and 2–7 cm (0.79–2.76 in) long; some species are deciduous, others evergreen. The flowers are small, inconspicuous yellow-green.