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 which is a hybrid with "Sorbus aria". The main pests for "S. aucuparia" are the apple fruit moth "Argyresthia conjugella" and the mountain-ash sawfly "Hoplocampa alpina". The rust fungus "Gymnosporangium cornutum" produces leaf galls. The leaves are not palatable to insects, but are used by insect larvae, including by the moth "Venusia cambrica", the case-bearer moth "Coleophora anatipennella", and leaf miners of the genus "Stigmella". The snail "Helix aspersa" feeds on the leaves. The plant can suffer from fire blight. Fossils of "Sorbus aucuparia" have been described from the fossil flora of Kızılcahamam district in Turkey, which is of early