Sorbus Sorbus Sorbus is a genus of about 100–200 species of trees and shrubs in the rose family, Rosaceae. Species of "Sorbus" ("s.l.") are commonly known as whitebeam, rowan, service tree, and mountain-ash. The exact number of species is disputed depending on the circumscription of the genus, and also due to the number of apomictic microspecies, which some treat as distinct species, but others group in a smaller number of variable species. Recent treatments treat "Sorbus" in a narrower sense to include only the pinnate leaved species of subgenus "Sorbus", raising several of the other subgenera to generic rank. "Sorbus" is
Mountain Ash, Rhondda Cynon Taf the Aberdare branch of the Merthyr Line of the Transport for Wales rail network. Further to Mountain Ash railway station, the village of Fernhill and Penrhiwceiber is also served by the Aberdare line. Bus services are operated by Stagecoach in South Wales. An early British railway line had developed from the industrial development within the South Wales Valleys, which with its core centred around Mountain Ash became known as the Mountain Ash Railway (MAR). Having developed from an early tramway, it became in the 1970s the last core of steam locomotive operations in the UK. Developed by Powell Duffryn as