Genus is the name given to plants united by distinct common characteristics, e.g., the genus Begonia. A genus is a member of a still larger botanical grouping called a family, and for begonias this is the Begoniaceae. Within each genus are many species. Individual plants of a species are alike and can breed with each other, breeding true from seed, although they can also be propagated from cuttings. The species name follows immediately after the name of the genus to which it belongs, e.g., Begonia sutherlandii, or in the abbreviated form B. sutherlandii, where the genus is begonia and the species is sutherlandii. The name of a species is always written in lower case letters, never capitals, and the genus and these words are usually set in italics. A smaller subdivision within a species is a subspecies, indicated in its name by the letters ssp., e.g., B. grandis ssp. evansiania, and yet another small subdivision, exemplified in the name B. cucullata var hookeri, indicates that this is a variety that differs slightly in its botanical structure. A hybrid is a plant derived from the interbreeding or cross-fertilization of two different species or their variants. This may be the result of either intentional or accidental crossing. A hybrid specifically cultivated for horticultural or garden purposes is known as a cultivar or variety. Most hybrids or cultivars have to be reproduced by vegetative methods such as cuttings (cloning), as their seeds do not come true, and a good number of these plants are, in fact, sterile.
Historicaldocuments show that the genus later known as Begonia had been discovered and classified under different names. One of these early finds was a plant which, although discovered in Mexico before 1577 by one Father Francisco Hernandez, was known only after 1651. This plant, a tuberous species, was given the name totoncaxoxo coyollin (subsequently identified as B. gracilis). However, even as early as the 14th century, Chinese writings describe a plant now identified as B. grandis Dryander. In 1690, Charles Plumier, a Franciscan Monk and botanist, discovered six plants in the West Indies, none of which fitted into any genus known at that time. The descriptions and botanical drawings allowed their identification as a totally new genus, which Plumier then dedicated to his patron, Michel Begon, hence the genus name, Begonia. Begon, who had a strong interest in botany, was at that time Governor (Intendant) of Haiti. Since that time, many species have been discovered, and discoveries continue to this day. It was, however, in the latter part of the 19th century that four separate finds led to a big rise of interest in begonias among horticulturists and collectors. This led in turn to the development of hybrids of the four more popular groups of begonias grown today.