Sorbus or uncertain parentage, have gained the Royal Horticultural Society’s Award of Garden Merit: 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
Sorbus aucuparia larger forest trees. In Central Europe it often grows in association with red elderberry, goat willow, Eurasian aspen, and silver birch. The plant is highly flammable and tends not to accumulate plant litter. Other species of the genus "Sorbus" easily hybridize with "S. aucuparia" and hybrid speciation can result; hybrids include "Sorbus × hybrida", a small tree with oval serrated leaves and 2 to 3 pairs of leaflets, which is a hybrid with "Sorbus × intermedia", and "Sorbus thuringiaca", a medium-size tree with elongated leaves and 1 to 3 pairs of leaflets that are sometimes fused at the central vein,