The rowans or mountain-ashes are shrubs or trees in the genus Sorbus of the rose family, Rosaceae. They are native throughout the cool temperate regions of the Northern Hemisphere, with the highest species diversity in the Himalaya, southern Tibet and parts of western China, where numerous apomictic microspecies occur. The name rowan was originally applied to the species Sorbus aucuparia and is also used for other species in the genus Sorbus.
Sorbus aucuparia, commonly called rowan and mountain-ash, is a species of deciduous tree or shrub in the rose family. It is a highly variable species, and botanists have used different definitions of the species to include or exclude trees native to certain areas. A recent definition includes trees native to most of Europe and parts of Asia, as well as northern Africa. The range extends from Madeira, the British Isles and Iceland to Russia and northern China. Unlike many plants with similar distributions, it is not native to Japan.
Sorbus is a genus of over 100 species of trees and shrubs in the rose family, Rosaceae. Species of Sorbus (s.l.) are commonly known as whitebeam, rowan, mountain-ash and service tree. The exact number of species is disputed depending on the circumscription of the genus, and also due to the number of apomictic microspecies, which some treat as distinct species, but others group in a smaller number of variable species. Recent treatments classify Sorbus in a narrower sense to include only the pinnate leaved species of subgenus Sorbus, raising several of the other subgenera to generic rank.
The whitebeams are members of the family Rosaceae, comprising the genus Aria. They are deciduous trees with simple or lobed leaves, arranged alternately. They are related to the rowans, and many of the endemic restricted-range apomictic microspecies of whitebeam in Europe are thought to derive from hybrids between the common whitebeam and the European rowan. Some are also thought to be hybrids with the wild service tree, and the service tree of Fontainebleau found in French woodlands.
Stewartia pseudocamellia, also known as Korean stewartia, Japanese stewartia, or deciduous camellia, is a species of flowering plant in the family Theaceae, native to Japan and Korea.
Sorbus cashmiriana, the Kashmir rowan, is a species of flowering plant in the family Rosaceae, native to the western Himalayas, including Kashmir.
Sorbus commixta, the Japanese rowan, is a species of flowering plant in the family Rosaceae, native to central and eastern China, Korea, Japan, and Sakhalin.
Sorbus oligodonta, also known as the kite-leaf rowan and white-fruited rowan, is a species of rowan found from the eastern Himalaya to south-central China, northern Vietnam and Myanmar.
Hedlundia hybrida, the oakleaf mountain ash, Swedish service-tree or Finnish whitebeam, is a species of whitebeam native to Norway, eastern Sweden, south-western Finland, and locally in Latvia.
Alniaria alnifolia, also called alder-leafed whitebeam, Korean whitebeam, or Korean mountain ash, Korean: 팥배나무; RR: Patbaenamu; MR: p'atpaenamu; lit. 'red bean pear tree' Chinese: 水榆花楸; pinyin: shui yu hua qiu; lit. 'water elm rowan', is a species of whitebeam native to eastern Asia in eastern and northern China, Taiwan, Korea and Japan.
Sorbus hupehensis, also known as Hupeh rowan or Hubei rowan, is a species of rowan native to central and western China. It is found between Qinghai and Gansu in the west, Yunnan in the south, Jiangxi in the southeast, and Shandong in the east.
Sorbus sargentiana, commonly known as Sargent's rowan is a species of flowering plant in the family Rosaceae. It is native to southwestern Sichuan and northern Yunnan in China, where it grows at altitudes of 2,000–3,200 m (6,560–10,500 ft).
Sorbus scalaris is a species of rowan. It is native to western Sichuan and Yunnan in China where it grows in mixed forests on mountain slopes at altitudes of 1600–3000 m. S. scalaris is a shrub or small tree, 3–7 m tall.
Sorbus californica, the California mountain ash, is an aggregate species of rowans native to western North America. The tree or bush is found in the mountains of California as the name suggests, but is not an ash, and this plant is sometimes cultivated. It has orange-red fruit and compound leaves that are toothed almost from base to apex, but is said to be most often confounded with the western North American species S. sitchensis which has pinkish fruit and leaflets with few teeth.
Sorbus frutescens is a species of rowan native to Gansu province of China. Often mistakenly lumped in with Sorbus koehneana, it is a very small tree reaching only 2 m at maturity, with white fruit against dark green pinnate leaves which turn shades of red and bronze in autumn.
Sorbus pseudohupehensis, the Chinese mountain ash, is a species of rowan native to Yunnan province in China. Available from commercial suppliers under a variety of names, it has gained the Royal Horticultural Society's Award of Garden Merit as an ornamental.
Sorbus rosea is a species of rowan native to Kashmir in Pakistan. It is a small tree with large pink flowers and berries, dark green leaves turning to red in the Autumn, and reddish bark with silver patches. It has gained the Royal Horticultural Society's Award of Garden Merit as an ornamental.
Sorbus ulleungensis is a species of rowan native to Ulleung Island of South Korea. Its cultivar 'Olympic Flame' has gained the Royal Horticultural Society's Award of Garden Merit as an ornamental. This medium-sized upright tree, growing to 8 m (26 ft), has large leaves which turn brilliant shades of red and orange in Autumn. Small white flowers in Spring are followed by bright red berries in the Autumn.
Alniaria yuana, Yu's whitebeam, is a species of flowering plant in the family Rosaceae, native to Chongqing, and western Hubei, China. Rare in the wild, it is usually found on steep ravine slopes over 2,000 m (6,600 ft) in elevation.
