Sorbus americana the red cascade mountain-ash, or "Sorbus americana" 'Dwarfcrown'. It is planted in gardens, and as a street tree. 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
Sorbus alnifolia fruit (persistent in other whitebeams), but genetic evidence places it close to "Sorbus aria". It is occasionally grown as an ornamental tree in northern Europe, primarily for its autumn colour. The cultivar 'Skyline' has been selected for its fastigiate growth. Sorbus alnifolia Sorbus alnifolia (syn. "Aria alnifolia"), also called alder-leafed whitebeam, Korean whitebeam, or Korean mountain ash, , is a species of whitebeam native to eastern Asia in eastern and northern China, Taiwan, Korea and Japan. "Sorbus alnifolia" is a medium-sized deciduous tree growing to 10–20 m tall with a trunk up to 30 cm diameter and grey bark; the