Sorbus arranensis rupicola") which is still found on Holy Isle. This hybrid species interbred with the rowan/mountain ash ("Sorbus aucuparia") to produce "S. arranesis". The bastard mountain ash ("Sorbus pseudofennica") arose from a further cross between "S. arranensis" and the mountain ash ("S. aucuparia"). Smart showed by using physical characteristics that the species were separate and not a result of random variation. Some overlap does however occur and this suggests that some hybridising may occur between the two species. Sorbus arranensis Sorbus arranensis, sometimes referred to as the Scottish or Arran whitebeam is a species of plant in the family Rosaceae. It
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