Think of passion fruit and the first thing that comes to mind is definitely not a plant that grows in the desert.  However, in the genus Adenia, part of the passion fruit family (Passifloriaceae), most species have developed an enlarged lower stem, or caudex, used to store water in extremely arid conditions.  Many species’ sap contain cyanogenic compounds and are very toxic.  Adenia are native to mostly the dry xeric coats of Eastern Africa, and some species extend down to South Africa.