Sorbus americana Sorbus americana The tree species Sorbus americana is commonly known as the American mountain-ash. It is a deciduous perennial tree, native to eastern North America. The American mountain-ash and related species (most often the European mountain-ash, "Sorbus aucuparia") are also referred to as rowan trees. "Sorbus americana" is a relatively small tree, reaching in height. The American mountain-ash attains its largest specimens on the northern shores of Lake Huron and Lake Superior. It resembles the European mountain-ash, "Sorbus aucuparia". Native to eastern North America; The berries of American mountain-ash are eaten by numerous species of birds and small mammals, including
Arran whitebeams between "S. arranensis" and the mountain ash ("S. aucuparia"). The "Sorbus" group are apomictic, producing viable seed without the need for pollination and fertilisation. Each time this hybrid cross occurs a new clone is effectively produced. Smart showed by using physical characteristics that the species were separate and not a result of random variation. Some overlap does however occur and this suggests that some hybridising may occur between the two species. A number of other "Sorbus" species have been produced in this way, such as the Devon whitebeam, the Bristol whitebeam, the Cheddar whitebeam, Irish whitebeam, Lancaster whitebeam, etc. All