Sorbus Sorbus 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. Recent treatments treat "Sorbus" in a narrower sense to include only the pinnate leaved species of subgenus "Sorbus", raising several of the other subgenera to generic rank. "Sorbus" is
Sorbus aucuparia asymmetrical at the bottom. "S. aucuparia" foliage grows in May and turns yellow in autumn or a dark red in dry locations. Buds of "S. aucuparia" are often longer than 1 cm and have flossy to felted hairs. These hairs, which disappear over time, cover dark brown to black bud scales. The terminal buds are oval and pointed and larger than axillary buds, which are narrow, oval and pointed, close to the twig, and often curved towards it. "S. aucuparia" is monoecious. It reaches maturity at age 10 and carries ample fruit almost every year. The plant flowers from May