Toni, I take it you are from Bangkok. I'd like to tell you that in the US we are growing a begonia brought back from Bangkok market that has not been identified, but is labeled B. U521 in our system for unidentified begonias awaiting identification. It is a wonderful begonia for the deep South U.S. because it tolerates heat and humidity so well. I am a hybridizer and have a number of hybrids that capitalizes on that trait that I am named Siam Crown, Siam King, and Emerald of Siam. I wonder if you know anyone there who knows begonias who might help us identify the true name of this plant. I am posting a photo of young plants propagated from its leaves. When large it has leaf petioles with hairs, radish, and leaf reverse is quite maroon. Thanks for your help.
