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 aucuparia be applied to other species in "Sorbus" subgenus "Sorbus", and mountain ash may be used for several other distantly related trees. The species is unrelated to the true ash trees (genus "Fraxinus"), which also carry pinnate leaves or the species "Eucalyptus regnans", also called mountain ash, native to Tasmania and Victoria in southeastern Australia. "S. aucuparia" was previously categorized as "Pyrus aucuparia". The author citation "Sorbus aucuparia" L. belongs to Carl Linnaeus. "Sorbus aucuparia" occurs as a tree or shrub that grows up to between 5 and 15 m in height. The crown is loose and roundish or irregularly shaped