Sorbus
Encyclopedia
Sorbus is a genus
of about 100–200 species of tree
s and shrub
s in the subfamily Maloideae
of the Rose family
Rosaceae
. Species of Sorbus (s.l.) are commonly known as whitebeam
, rowan
, service tree
, and mountain ash
. 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 treat Sorbus in a narrower sense to include only the pinnate leaved species of subgenus
Sorbus, raising several of the other subgenera to generic rank.
Sorbus is unrelated to the true ash trees which belong to the genus Fraxinus, although the leaves are superficially similar.
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 species are used as food plants by the larva
e of some moth
species—see list of Lepidoptera that feed on Sorbus.
.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of about 100–200 species of tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
s and shrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
s in the subfamily Maloideae
Maloideae
The Maloideae C.Weber are the apple subfamily, a grouping used by some taxonomists within the rose family, Rosaceae. Recent molecular phylogenetic evidence has shown that the traditional Spiraeoideae and Amygdaloideae form part of the same clade as the traditional Maloideae, and the correct name...
of the Rose family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Rosaceae
Rosaceae
Rosaceae are a medium-sized family of flowering plants, including about 2830 species in 95 genera. The name is derived from the type genus Rosa. Among the largest genera are Alchemilla , Sorbus , Crataegus , Cotoneaster , and Rubus...
. Species of Sorbus (s.l.) are commonly known as whitebeam
Whitebeam
The whitebeams are members of the Rosaceae family, comprising subgenus Aria of genus Sorbus, and hybrids involving species of this subgenus and members of subgenera Sorbus, Torminaria and Chamaemespilus. They are deciduous trees with simple or lobed leaves, arranged alternately...
, rowan
Rowan
The rowans or mountain-ashes are shrubs or small trees in genus Sorbus of family Rosaceae. They are native throughout the cool temperate regions of the Northern Hemisphere, with the highest species diversity in the mountains of western China and the Himalaya, where numerous apomictic microspecies...
, service tree
Service Tree
Sorbus domestica is a species of Sorbus native to western, central and southern Europe, northwest Africa , and southwest Asia .It is a deciduous tree growing to 15–20 m tall with a...
, and mountain ash
Sorbus aucuparia
Sorbus aucuparia , is a species of the genus Sorbus, native to most of Europe except for the far south, and northern Asia...
. The exact number of species is disputed depending on the circumscription of the genus, and also due to the number of apomictic
Apomixis
In botany, apomixis was defined by Winkler as replacement of the normal sexual reproduction by asexual reproduction, without fertilization. This definition notably does not mention meiosis...
microspecies
Apomixis
In botany, apomixis was defined by Winkler as replacement of the normal sexual reproduction by asexual reproduction, without fertilization. This definition notably does not mention meiosis...
, which some treat as distinct species but others group in a smaller number of variable species. Recent treatments treat Sorbus in a narrower sense to include only the pinnate leaved species of subgenus
Subgenus
In biology, a subgenus is a taxonomic rank directly below genus.In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the Tiger Cowry of the Indo-Pacific, Cypraea tigris Linnaeus, which...
Sorbus, raising several of the other subgenera to generic rank.
Sorbus is unrelated to the true ash trees which belong to the genus Fraxinus, although the leaves are superficially similar.
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 rowanRowanThe rowans or mountain-ashes are shrubs or small trees in genus Sorbus of family Rosaceae. They are native throughout the cool temperate regions of the Northern Hemisphere, with the highest species diversity in the mountains of western China and the Himalaya, where numerous apomictic microspecies...
(primarily in the UK) or mountain ash (in both North America and the UK), with compound leaves usually hairless or thinly hairy below; fruit carpels not fused; type species Sorbus aucupariaSorbus aucupariaSorbus aucuparia , is a species of the genus Sorbus, native to most of Europe except for the far south, and northern Asia...
(European rowan). Distribution: cool-temperate Northern HemisphereNorthern HemisphereThe Northern Hemisphere is the half of a planet that is north of its equator—the word hemisphere literally means “half sphere”. It is also that half of the celestial sphere north of the celestial equator...
. (Genus Sorbus s.s.)
- Sorbus subgenus Aria (genus Aria), the whitebeamWhitebeamThe whitebeams are members of the Rosaceae family, comprising subgenus Aria of genus Sorbus, and hybrids involving species of this subgenus and members of subgenera Sorbus, Torminaria and Chamaemespilus. They are deciduous trees with simple or lobed leaves, arranged alternately...
, with simple leaves usually strongly white-hairy below (hence the name, from German Weissbaum, 'white tree'); fruit carpels not fused; type species Sorbus ariaSorbus ariaSorbus aria , the Whitebeam or Common Whitebeam is a deciduous tree, compact and domed, with few upswept branches; it generally favours dry limestone and chalk soils. The hermaphrodite cream-white flowers appear in May, are insect pollinated, and go on to produce scarlet berries, which are often...
(common whitebeam). Distribution: temperate EuropeEuropeEurope is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
& AsiaAsiaAsia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
.
- Sorbus subgenus Micromeles (genus Aria), an indistinct group of a few east Asian species (e.g. Sorbus alnifoliaSorbus alnifoliaSorbus alnifolia Alder-leafed Whitebeam or Korean Whitebeam; ) is a species of whitebeam native to eastern Asia in China, Korea and Japan.- Description :...
, Korean whitebeam) with narrow leaves; doubtfully distinct from and often included in subgenus Aria. Distribution: temperate northeast AsiaAsiaAsia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
.
- 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 AfricaNorth AfricaNorth Africa or Northern Africa is the northernmost region of the African continent, linked by the Sahara to Sub-Saharan Africa. Geopolitically, the United Nations definition of Northern Africa includes eight countries or territories; Algeria, Egypt, Libya, Morocco, South Sudan, Sudan, Tunisia, and...
, warm-temperate EuropeEuropeEurope is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, West Asia.
- Sorbus subgenus Torminaria (genus Torminalis), with rather maple-like lobed leaves with pointed lobes; fruit carpels not fused; just one species, Sorbus torminalis (Wild Service Tree). Distribution: temperate EuropeEuropeEurope is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, south to the mountains of North AfricaNorth AfricaNorth Africa or Northern Africa is the northernmost region of the African continent, linked by the Sahara to Sub-Saharan Africa. Geopolitically, the United Nations definition of Northern Africa includes eight countries or territories; Algeria, Egypt, Libya, Morocco, South Sudan, Sudan, Tunisia, and...
and east to the CaucasusCaucasusThe Caucasus, also Caucas or Caucasia , is a geopolitical region at the border of Europe and Asia, and situated between the Black and the Caspian sea...
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 EuropeEuropeEurope is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
.
- Hybrids are common in the genus, including many between the subgenera; very often these hybrids are apomicticApomixisIn botany, apomixis was defined by Winkler as replacement of the normal sexual reproduction by asexual reproduction, without fertilization. This definition notably does not mention meiosis...
(self-fertile without pollination), so able to reproduce clonally from seed without any variation. This has led to a very large number of microspeciesApomixisIn botany, apomixis was defined by Winkler as replacement of the normal sexual reproduction by asexual reproduction, without fertilization. This definition notably does not mention meiosis...
, particularly in western Europe (including Britain) and parts of China.
Sorbus species are used as food plants by the larva
Caterpillar
Caterpillars are the larval form of members of the order Lepidoptera . They are mostly herbivorous in food habit, although some species are insectivorous. Caterpillars are voracious feeders and many of them are considered to be pests in agriculture...
e of some moth
Moth
A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. Moths form the majority of this order; there are thought to be 150,000 to 250,000 different species of moth , with thousands of species yet to be described...
species—see list of Lepidoptera that feed on Sorbus.
Wine
Sorbus was also a fortified Finnish fruit wine flavoured with rowan berries (sold until August 21, 2010). Sorbus domestica is used to flavour some apple wines, see apfelweinApfelwein
Cider in Germany is called Apfelwein , as the German language has not used the word cider. It is also regionally known as ebbelwoi, äppler, stöffsche, apfelmost , viez , and saurer most . It has an alcohol content of 5.5%–7% and a tart, sour taste...
.
Further reading
- Price, D.T. 2007. One-way introgressive hybridisation between Sorbus aria and S. torminalis (Rosaceae) in southern Britain. Watsonia. 26: 419–431.