Carob tree (Ceratonia siliqua) is an evergreen shrub or tree native to the Mediterranean region, cultivated for its edible seed pods. Also known as St John's Bread, the flesh of the pods tastes similar to sweetened cocoa, but contains no caffeine or other psychoactive substances and is often used as a hypoallergenic, drug-free substitute. Mixed with saturated fats like butter fat or palm oil, it is often used to make a sweet chocolate-like confection that is usually referred to simply as "carob."

This tree grows up to 10 m high. The crown is broad and semi-spherical, supported by a thick trunk, brown rough bark and sturdy branches. Leaves are 10–20 cm long, alternate, pinnate, and may or may not have a terminal leaflet. The flowers are a green-tinted red, small, numerous, and about 6–12 mm long. They are spirally arranged along the inflorescence axis in catkin-like racemes borne on spurs from old wood and even on the trunk (cauliflory). The fruit is a pod which can be elongated, compressed, straight or curved, and thickened at the sutures. Carob is a member of the legume family, and as such its roots host bacteria which convert atmospheric nitrogen into nitrates which can be used by plants to make protiens.

These trees cannot withstand waterlogging, although the root system is usually deep. It grows well in warm temperate and subtropical areas and tolerates hot and humid coastal areas. It is a xerophytic (drought-resistant) species, well adapted to the ecological conditions of the Mediterranean region.

Carob is not a staple food in the Mediterranean, but provides good sustenance during times when other crops are scarce and is a traditional feed for livestock. It is most commonly put in cakes, icing, and sometimes cookies. The seeds themselves, also known as locust bean, are used as animal feed and to extract locust bean gum , a thickening agent.

Carob pods were the most important source of sugar before sugarcane and sugar beets became widely available. Nowadays, the seeds are processed for the use in cosmetics, curing tobacco, and making paper. Because of their uniform size, the seeds were also used to weigh precious gemstones. The word carat is derived from the carob tree. The scientific name of the carob tree derives from the Greek keras, "horn", and Latin siliqua, alluding to the hardness and shape of the pod.

See also

• tamarind (Tamarindus indica)
• list of fruits

References and external links

• Fruits of Warm Climates: Carob
• Carob entry at Encyclopedia.com
• Carob recipes at cooks.com
• World Agroforestry Centre