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 tannin, and vitamin C. The seeds contain glycoside. "Sorbus aucuparia" has a chromosome number of 2"n"=34. "Sorbus aucuparia" is found in five subspecies: It can be found in almost all of Europe and the Caucasus up to Northern Russia and Siberia, but it is not native to Southern Spain, Southern Greece, Sardinia, the Balearic Islands, the Azores, and the Faroe Islands. The species was introduced as an ornamental species in North America. It is widespread from plains to mountains up to the tree line where it grows as the only deciduous tree species among krummholz. In the Alps it grows