Baobab. The massive, usually squat cylindrical trunk gives rise to thick tapering branches resembling a root-system, which is why it has often been referred to as the upside-down tree. Regarded as the largest succulent plant in the world, the baobab tree is steeped in a wealth of mystique, legend and superstition wherever it occurs in Africa. It is a tree that can provide, food, water, shelter and relief from sickness.