Ceratonia comprises two species: the common C. siliqua of the Mediterranean and Middle East, and the rare and poorly known C. oreothauma Hillc., G.P. Lewis & Verdc. of Somalia and Oman (Hillcoat et al. 1980). Carobs are evergreen trees or shrubs with dense, broad, rounded crowns. They are unarmed, and have minute, caducous stipules. The leaves are pinnate with an even number of leaflets (paripinnate), usually two to five pairs; they are typically glossy, dark green and leathery. Ceratonia species may be dioecious, polygamous or both. The axillary inflorescences are short, catkin-like racemes bearing 30–50 flowers. The flowers are 5-merous with a deciduous calyx and no petals. The fruit is a pendent, indehiscent legume containing a sweet mucilaginous pulp and 5–15 seeds (Ball 1968, Allen & Allen 1981).