Arran whitebeams complex fashion, which involved the common whitebeam ("Sorbus aria") giving rise to the tetraploid rock whitebeam ("Sorbus rupicola") which is still found on Holy Isle. This species is able to survive at higher altitudes and therefore occupies a less competitive niche with fewer tree species able to tolerate the harsher conditions. The rock whitebeam interbred with the rowan / mountain ash ("Sorbus aucuparia") to produce the hybrid, a fertile separate species the Scottish whitebeam ("Sorbus arranesis") which grows well in this zone of reduced competitive growth at higher altitudes. The bastard mountain ash ("Sorbus pseudofennica") arose from a further cross
Mountain Ash East Cymru group on Rhondda Cynon Taff Council since 1996. The Plaid Cymru numbers doubled to 18 after the May 2017 election and are the official opposition on the council. Mountain Ash East Mountain Ash East is a community and coterminous electoral ward in Rhondda Cynon Taf, Wales. It primarily includes the part of the village of Mountain Ash east of the River Cynon. The community was formed in 2016 when the larger community of Mountain Ash was divided into East and West to match the ward boundaries. The Mountain Ash East community came into effect on 1 December 2016 following