Desert Rose, also known as Adenium obesum, is a nice little flowering shrub in the Oleander family (Apocynaceae), more commonly called the Dogbane family for some reason, from the nether regions of the Sahara Desert, and thereabouts.
They like a lot of sun and a lot of heat. We tend to grow them in normal indoor Berkeley conditions, in a sunny window, but not particularly hot, so they tend to be less leafy for us, and grow a lot slower too. But they are still very reliable bloomers, even into and through the winter.
Colors vary, and some people name the differently-colored-flower-cultivars so that people can collect them all. But we don’t. I consider it natural variation.