Sorbus is a genus of about 100–200 species of trees and shrubs in the Rose family Rosaceae. Species of Sorbus (s.l.) are commonly known as whitebeam, rowan, service tree, and mountain-ash. The exact number of species is disputed depending on the circumscription of the genus, and also due to the number of apomictic microspecies, which some treat as distinct species but others group in a smaller number of variable species.