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
Burrington Combe as a Site of Special Scientific Interest in 1952. The calcareous grasslands support a diverse flora which includes Salad burnet ("Sanguisorba minor"), Knapweed ("Centaurea scabiosa" and "Centaurea nigra"), Rock-rose ("Helianthemum nummularium") and Wild thyme ("Thymus praecox"). On the higher, more acidic, slopes Goldenrod ("Solidago virgaurea"), Wood sage ("Teucrium scorodonia") and Common Bent ("Agrostis capillaris") can be found. There are also scrub plants including Hawthorn ("Crataegus monogyna"), Mountain ash ("Sorbus aucuparia"), gorse ("Ulex europaeus") and Elder ("Sambucus nigra"). Several of the caves support bat populations. Geologically it is recognised as a fluvial karst feature which partly intersects a buried and filled