The Carob tree (Ceratonia siliqua) is best known for its edible seeds that are used, among other things, as a chocolate substitute. It is a tree that grows well in dry climates, which would explain its relative abundance in Southern Spain were the Carob tree and the Holm Oak can be found on most "fincas" (small farms or country houses). The images I have used in this post are from several trees not far from my home.
The leaves of the Carob tree are even-pinnately compound with the individual leaflets being slightly oblong with a round base and about two inches in length. The venation is pinnate.
The seedpods of the Carob tree look a lot like green-beans. Before they turn ripe they are bright, shinny green and measure about 5-7 inches in length. When ripe they darken to almost pure black and become somewhat withered. The seed pods hand in small clusters from the primary and secondary branches and I have even seen them growing right out of the main trunk. Judging by what I have seen the clusters can contain from two to seven seed pods.
The image below shows the edible carob seeds in a ripe seed pods that I carefully opened up. These seeds can be eaten right out of the seed pop or can be used to make a number of things such as a chocolate substitute, flower, molasses, alcohol, etc. Many of these products are made from ceratonia (also known as locust bean gum or Carob bean gum).
One interesting thing about the tree itself is its highly gnarled trunk when it get old. Near where I live most of the Carob trees have super gnarled trunks like the image below. Once while out on a hike I came across one with a large broken branch that left the wood exposed. I was suprised by how red the wood was. Later a local man told me that this tree is used by local wood workers and carvers to make stair rails, small furniture and carvings.