Rex begonias are the showboats of the begonia world and are a type of rhizomatous begonia that are grown for their multicolored leaves. 

The leaves come in every color, pattern and shade, and every size and shape. All Rex Cultorum types are descended from the Indian species B. rex that was crossed with other types of rhizomatous begonias. 

Rex begonias do bloom but are not grown for their blooms which pale in comparison to their spectacular leaves.