Rowan Several of the Asian species are widely cultivated as ornamental trees. North American native species in the subgenus "Sorbus (Sorbus)" include the American mountain-ash "Sorbus americana" and Showy mountain-ash "Sorbus decora" in the east and Sitka mountain-ash "Sorbus sitchensis" in the west. Numerous hybrids, mostly behaving as true species reproducing by apomixis, occur between rowans and whitebeams; these are variably intermediate between their parents but generally more resemble whitebeams and are usually grouped with them (q.v.). Rowans are excellent small ornamental trees for parks, gardens and wildlife areas. Several of the Chinese species, such as White-fruited rowan ("Sorbus glabrescens") are
Sorbus aucuparia The tallest "S. aucuparia" in the United Kingdom stands in the Chiltern Hills in South East England. This exceptional specimen is 28 m tall and has a trunk diameter of 56 cm. In Germany, an unusually large specimen is located near Wendisch Waren, a village in Mecklenburg-Vorpommern. This tree stands at more than 15 m tall, is around 100 years old, and has a diameter of 70 cm. The tallest known "S. aucuparia" in Ireland is an 18 m tall specimen at Glenstal Abbey, County Limerick. "Sorbus aucuparia" is pollinated by bees and flies. Its seeds are not digested by