Desert rose tree (Adenium obesum sokotranum) in a rocky landscape. This subspecies of the desert rose is endemic to the Socotran archipelago of islands, meaning that it is found nowhere else. It has a thick, bottle-shaped trunk to conserve water. The islanders traditionally use the poisonous bark of the desert rose to kill small fish for bait. They also tie strips of the bark around the necks of their livestock to deter wild cats. Socotra is located in the Indian Ocean at the mouth of the Gulf of Aden, 340 kilometres (km) from mainland Yemen and 250km from the coast of Somalia. Its isolation has led to the evolution of a unique flora and fauna.