''Sorbus'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of over 100

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...

of trees and shrubs in the rose

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Rosaceae Rosaceae (), the rose family, is a medium-sized family of flowering plants that includes 4,828 known species in 91 genera. The name is derived from the type genus ''Rosa''. Among the most species-rich genera are '' Alchemilla'' (270), ''Sorb ...

. Species of ''Sorbus'' (''s.l.'') are commonly known as

whitebeam The whitebeams are members of the family Rosaceae, comprising subgenus ''Aria'' (or, according to some authorities, its own genus) of genus ''Sorbus'', and hybrids involving species of this subgenus and members of subgenera ''Sorbus'', ''Torminar ...

rowan The rowans ( or ) 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 ...

( mountain-ash) and service tree. The exact number of species is disputed depending on the

circumscription Circumscription may refer to: *Circumscribed circle * Circumscription (logic) *Circumscription (taxonomy) *Circumscription theory, a theory about the origins of the political state in the history of human evolution proposed by the American anthrop ...

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 treatmentsRobertson, K. R., J. B. Phipps, J. R. Rohrer, and P. G. Smith. 1991. A Synopsis of Genera in Maloideae (Rosaceae). ''Systematic Botany'' 16: 376–394.McAllister, H. 2005. The Genus ''Sorbus'': Mountain Ash and Other Rowans. Richmond, Surrey, UK: Royal Botanic Gardens, Kew.Potter, D., T. Eriksson, R. C. Evans, S.-H. Oh, J. E. E. Smedmark, D.R. Morgan, M. S. Kerr, and C. S. Campbell. (2007). Phylogeny and classification of Rosaceae. ''Plant Systematics and Evolution''. 266(1–2): 5–43.Campbell C. S., R. C. Evans, D. R. Morgan, T. A. Dickinson, and M. P. Arsenault. 2007. Phylogeny of subtribe Pyrinae (formerly the Maloideae, Rosaceae): Limited resolution of a complex evolutionary history. ''Pl. Syst. Evol.'' 266: 119–145. classify ''Sorbus'' in a narrower sense to include only the

pinnate Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, an ...

leaved species of

subgenus In biology, a subgenus (plural: subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between ...

''Sorbus'', raising several of the other subgenera to generic rank. ''Sorbus'' is not closely related to the true ash trees which belong to the genus ''

Fraxinus ''Fraxinus'' (), commonly called ash, is a genus of flowering plants in the olive and lilac family, Oleaceae. It contains 45–65 species of usually medium to large trees, mostly deciduous, though a number of subtropical species are evergr ...

'', although the leaves are superficially similar.

Genus

As treated in its broad sense, the genus is divided into two main and three or four small subgenera (with more recent generic assignments in parentheses): *''Sorbus'' subgenus ''Sorbus'' (genus ''Sorbus'' s.s.), commonly known as the

(primarily in the UK) or mountain-ash (in Ireland, North America and the UK), with compound leaves usually hairless or thinly hairy below; fruit carpels not fused; the type is ''

Sorbus aucuparia ''Sorbus aucuparia'', commonly called rowan (UK: /ˈrəʊən/, US: /ˈroʊən/) 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 ...

'' (European rowan). Distribution: cool-temperate

Northern Hemisphere The Northern Hemisphere is the half of Earth that is north of the Equator. For other planets in the Solar System, north is defined as being in the same celestial hemisphere relative to the invariable plane of the solar system as Earth's Nort ...

. (Genus ''Sorbus'' s.s.) *''Sorbus'' subgenus ''Aria'' (genus ''Aria''), the

, with simple leaves usually strongly white-hairy below (hence the name, from German ''Weissbaum'', 'white tree'); fruit carpels not fused; the type is ''

Sorbus aria ''Sorbus aria'' (syn. ''Aria nivea''), the whitebeam or common whitebeam, is a deciduous tree, the type species of the subgenus ''Sorbus'' subg. ''Aria'' of the genus ''Sorbus''. It is native to most of Europe as well as North Africa (Algeria, Mo ...

'' (common whitebeam). Distribution: temperate

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an are ...

. *''Sorbus'' subgenus ''Micromeles'' (genus ''Micromeles''), an indistinct group of a few east Asian species (e.g. '' Sorbus alnifolia'', Korean whitebeam) with narrow leaves; doubtfully distinct from and often included in subgenus ''Aria''. Distribution: temperate northeast

. *''Sorbus'' subgenus ''Cormus'' (genus ''Cormus''), with compound leaves similar to subgenus ''Sorbus'', but with distinct fused carpels in the fruit; just one species, '' Sorbus domestica'' (True Service Tree). Distribution:

North Africa North Africa, or Northern Africa is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region, and it is sometimes defined as stretching from the Atlantic shores of Mauritania in ...

, warm-temperate

West Asia Western Asia, West Asia, or Southwest Asia, is the westernmost subregion of the larger geographical region of Asia, as defined by some academics, UN bodies and other institutions. It is almost entirely a part of the Middle East, and includes ...

. *''Sorbus'' subgenus ''Torminaria'' (genus ''Torminalis''), with rather maple-like lobed leaves with ''pointed'' lobes; fruit carpels not fused; just one species, ''

Sorbus torminalis ''Sorbus torminalis'', with common names wild service tree, chequers, and checker tree, is a species of tree in the mountain ash or rowan genus (''Sorbus'') of the rose family (Rosaceae), that is native to Europe, parts of northern Africa and we ...

'' (Wild Service Tree). Distribution: temperate

, south to the mountains of

and east to the

Caucasus The Caucasus () or Caucasia (), is a region between the Black Sea and the Caspian Sea, mainly comprising Armenia, Azerbaijan, Georgia, and parts of Southern Russia. The Caucasus Mountains, including the Greater Caucasus range, have historica ...

ranges. *''Sorbus'' subgenus ''Chamaemespilus'' (genus ''Chamaemespilus''), a single shrubby species '' Sorbus chamaemespilus'' (false medlar) with simple, glabrous leaves and pink flowers with erect sepals and petals. Distribution: mountains of southern

. *''Sorbus'' subgenus ''Umbellata'' (genus ''Umbellata''), Sorbus umbellata ssp. flabellifolia has oval with saw-like indentations along the upper edges of the leaf. It produces an edible but not high quality fruit. Distribution: mountains of

Lebanon Lebanon ( , ar, لُبْنَان, translit=lubnān, ), officially the Republic of Lebanon () or the Lebanese Republic, is a country in Western Asia. It is located between Syria to the north and east and Israel to the south, while Cyprus lie ...

and specifically Ehden and Shouf Nature Reserves at elevations between 1300 to 1800 meters. *Hybrids are common in the genus, including many between the subgenera; very often these hybrids are

apomictic In botany, apomixis is asexual reproduction without fertilization. Its etymology is Greek for "away from" + "mixing". This definition notably does not mention meiosis. Thus "normal asexual reproduction" of plants, such as propagation from cuttin ...

(self-fertile without pollination), so able to reproduce clonally from seed without any variation. This has led to a very large number of

microspecies In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

, particularly in western Europe (including Britain) and parts of China. ''Sorbus'' species are used as food plants by the

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. ...

e of some

moth Moths are a paraphyletic group of insects that includes all members of the order Lepidoptera that are not butterflies, with moths making up the vast majority of the order. There are thought to be approximately 160,000 species of moth, many of w ...

species—see list of Lepidoptera that feed on ''Sorbus''. '' Sorbus domestica'' is used to flavour some apple wines, see ''

Apfelwein ''Apfelwein'' ( German, 'apple wine'), or ''Viez'' ( Moselfranken, Saarland, Trier, ''vice'') or ''Most'' ( Austria, Switzerland, South Germany, ''must'') are German words for cider. It is made from a mix of sour tasting apples, such as "Bohn ...

''.

Species

Uses

Ornamental trees

''Sorbus'' species are cultivated as ornamental trees for parks and gardens and as avenue trees, and have given rise to several

cultivars A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture, ...

. The following, of mixed or uncertain parentage, have gained the

Royal Horticultural Society The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity. The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr (Nor ...

’s

Award of Garden Merit The Award of Garden Merit (AGM) is a long-established annual award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions. History The Award of Garden Merit ...

: *’Eastern Promise’ (purple autumn colour, pink berries) *’Leonard Messel’ (small tree to 4m, pink berries) *’Wisley Gold’ (yellow berries)

Gallery

File:Punetav pihlapuu.jpg, Red rowan File:Rowan in the garden of Eastern Siberia.jpg, Rowan in the garden of

Eastern Siberia Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part of ...

References