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 × hybrida midrib as separate leaflets. All three polyploid species are apomictic species which breed true without pollination. "Sorbus" × "hybrida" is grown as an ornamental tree in northern Europe, and is locally naturalised in the British Isles. The cultivar 'Gibbsii' has gained the Royal Horticultural Society's Award of Garden Merit. Sorbus × hybrida Sorbus "×" hybrida, the oakleaf mountain ash, Swedish service-tree or Finnish whitebeam, is a hybrid species of whitebeam native to Scandinavia in Norway, eastern Sweden, and southwestern Finland, and locally in the Baltic States in Latvia. It is a medium-sized deciduous tree growing to 10–15 m tall with