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
Berry Mountain Pond, , presumed the highest natural pond in the state of Massachusetts, is located on the ridge between Berry Mountain and Berry Hill to the north. The west side and summits of Berry Mountain are located within Hancock, Massachusetts; the east slopes are located within Pittsfield. The ridgeline continues south from Berry Mountain as Pine Mountain and Tower Mountain; it continues north as Berry Hill. Berry Mountain is bordered by West Hill to the west across the Wyomanock Creek valley. The west side of the mountain drains into Berry Pond Creek, then Wyomanock Creek, thence into Kinderhook Creek, the Hudson