The Director of Nomenclature Department of the American Begonia Society has written what is- as of the present- a definitive reference work on begonias,- their families, their varieties, their culture. The text is not intended for the amateur gardener, but for the horticulturist, botanist, specialist in the field. Some space is given in rather bald terms to the history of their discovery, their uses, their extensive cultivation, until they number up in the thousand. This book identifies the groups and species.