Adenium obesum, the desert rose is native to the Sahel in Africa. It is a (worthy) challenge to grow outdoors in San Diego because it likes conditions to be hot and humid and the soil to drain well so that roots remain dry. The need for humidity and mild winter nights means a greenhouse is best, especially inland. All parts of the plant are visually interesting (and poisonous) but the many subspecies, flower colors, and ability to cross-graft, make it a rewarding hobby plant.