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 damp, acidic, low on nutrients, sandy, and loose. It often grows in stony soil or clay soil, but also sandy soil or wet peat. The plant grows best on fresh, loose, and fertile soil, prefers average humidity, and does not tolerate saline soil or waterlogging. It can be found in light woodland of all kinds and as a pioneer species over fallen dead trees or in clearcuttings, and at the edge of forests or at the sides of roads. Seeds of "S. aucuparia" germinate easily, so the plant may appear on inaccessible rock, ruins, branch forks, or on hollow trees.