The Desert Rose (Adenium obesum) is a perennial succulent that's native to Arabia’s semi-arid regions and eastern as well as western tropical Africa.
These are shrubby-tree type plants that have fleshy, bottle-shaped trunks. The bulbous trunks can be half or completely buried in the soil. They are unusual plant specimens that have beautiful flowers, making them quite the conversation piece.
While desert roses are easy to grow, they don't do well outdoors if the temperatures fall below 59 degrees. Because they make excellent container plants, they do quite well inside homes and greenhouses. For this reason, they're popular to use as bonsai plants.
Source : Mar 30, 2009 by Chris Mclaughlin
: http://www.suite101.com/content/how-to-grow-the-desert-rose-adenium-obesum-a106118
