Jean your Begonia looks like what I've seen as Wax Begonia's. They do like more Sun and less Water. The Dragon Wings that I'm familar with are more like slender Angel Wing Begonias.
I've grown the Cassia's here also. They are a host plant for the Sulphur Butterflies tho, so get chewed up. I hate to kill off the caterpillars so I just quit growing it, they use the native stuff in the area. I don't have as many Sulphur's now tho, which I kinda miss.
