The Carob is a long lived tree which can obtain a height of around 12 to 15 metres and extends to a wide canopy. It is native to the Eastern Mediterranean area where it thrives in arid conditions but is now cultivated commercially in warm climates as the pods have an important economic value, known for at least 4,000 years.

Known in Spanish as “Algarrobo”, it is an evergreen tree with oval glossy green leaves and a short wide trunk which on mature specimens is rough and gnarled. The scientific name of the carob tree, Ceratonia siliqua derives from the Greek word keras, meaning horn, and the Latin siliqua meaning pod, alluding to the hardness and shape of the pod. It is a member of the botanical Fabaceae family of plants (leguminous beans and peas).

Carob flowers and fruit grow out of older branches, twigs and even the trunk of the trees. (This botanical phenomenon is known as “cauliflory”.) The flowers are insignificant as they have no petals (similar to catkins) and are green/yellow or red in colour, these being mostly on separate male and female trees. The pollen from the male flower needs to be distributed by insects to the female flowers from which the beans then develop. The carob tree flowers in September and October with the developing carob pods slowly gaining the appearance of green broad beans. It takes 11 months to develop into a pod that is flattish, shiny brown and around 15 to 20cm long.

The Carob tree produces little fruit until it reaches15 years old, although it can live for 100 years with a large tree producing one ton of beans in a harvest. It is now grown commercially in Spain, Portugal, France, Italy, Africa, California, Arizona, Mexico, South America and Australia,

A long hot summer ensures a plentiful crop of the long beans which are collected by hand from the tree or later from the ground after they fall. Many small-holdings will still have a carob tree to give a supply of fodder to their animals through the winter. They are also gathered and taken to some agricultural co-operatives for bulk re-sale.

This tree grows up to 10 metres (33 ft) tall. The crown is broad and semi-spherical, supported by a thick trunk with brown rough bark and sturdy branches. Leaves are 10 to 20 centimetres (3.9 to 7.9 in) long, alternate, pinnate, and may or may not have a terminal leaflet. It is frost-tolerant.

Most carob trees are dioecious. The trees blossom in autumn (September–October). The flowers are small and numerous, spirally arranged along the inflorescence axis in catkin-like racemes borne on spurs from old wood and even on the trunk (cauliflory); they are pollinated by both wind and insects. Male flowers produce a characteristic odour, resembling semen.[3] The fruit is a pod that can be elongated, compressed, straight or curved, and thickened at the sutures. The pods take a full year to develop and ripen. The ripe pods eventually fall to the ground and are eaten by various mammals, thereby dispersing the seed. Likewise, carob consumed by humans is actually the dried (and sometimes roasted) pod, and not the ‘nuts’ or seeds.