Rex begonias are rhizomatous in growth habit, but are grouped separately because of the colour of their leaves. The original Rex begonia was brought from Assam in India in 1856, by mistake, in a collection of orchids.

Leaf colourings are said to run the gambit of shades of precious metals – gold, silver, platinum, etc and precious gems – amethyst, ruby, garnet, topaz, emerald and opal. The leaf textures follow that of beautiful fabrics such as silk, satin, velvet, brocade, crepe, tweed and soft woolens.