''Sorbus eminens'', the round-leaved whitebeam, sometimes classified as ''Aria eminens'' when the ''

Aria In music, an aria ( Italian: ; plural: ''arie'' , or ''arias'' in common usage, diminutive form arietta , plural ariette, or in English simply air) is a self-contained piece for one voice, with or without instrumental or orchestral accompa ...

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 betw ...

of ''

Sorbus ''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 dep ...

'' is elevated to full

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 n ...

, is a species of

plant Plants are predominantly Photosynthesis, photosynthetic eukaryotes of the Kingdom (biology), kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all curr ...

in the family

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), '' Sorbu ...

. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found els ...

Great Britain Great Britain is an island in the North Atlantic Ocean off the northwest coast of continental Europe. With an area of , it is the largest of the British Isles, the largest European island and the ninth-largest island in the world. It is ...

. It is threatened by

habitat loss Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

Description

As part of the ''

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 ...

'' complex, ''Sorbus eminens'' is broadly similar to ''S. aria''. It is a shrub or small tree up to tall. The undersides of the leaves are greyish-white due to the many hairs. The leaves are more or less round, usually with a length 1–1.3 times the width, rarely up to 1.5 times as long as wide; they usually have 9–11 veins on either side. The leaf margins usually have a single series of teeth ("uniserrate") although there can be evidence of a second series ("biserrate"). The fruits have many

lenticel A lenticel is a porous tissue consisting of cells with large intercellular spaces in the periderm of the secondarily thickened organs and the bark of woody stems and roots of dicotyledonous flowering plants. It functions as a pore, providing a ...

s, small and large, mainly towards the base. p. 209.

Distribution and habitat

''Sorbus eminens'' is

to parts of south-west England and south Wales. It is considered to be native to calciferous woodland in north

Somerset ( en, All The People of Somerset) , locator_map = , coordinates = , region = South West England , established_date = Ancient , established_by = , preceded_by = , origin = , lord_lieutenant_office =Lord Lieutenant of Somerset , lor ...

, west

Gloucestershire Gloucestershire ( abbreviated Glos) is a county in South West England. The county comprises part of the Cotswold Hills, part of the flat fertile valley of the River Severn and the entire Forest of Dean. The county town is the city of Gl ...

Herefordshire Herefordshire () is a county in the West Midlands of England, governed by Herefordshire Council. It is bordered by Shropshire to the north, Worcestershire to the east, Gloucestershire to the south-east, and the Welsh counties of Monmouthshire ...

and Monmouthshire. It has also been recorded in Sutton Park,

Birmingham Birmingham ( ) is a city and metropolitan borough in the metropolitan county of West Midlands in England. It is the second-largest city in the United Kingdom with a population of 1.145 million in the city proper, 2.92 million in the We ...

, well outside its expected range, where it is assumed to have been planted originally.

Evolution

''S. eminens'' is a tetraploid, resulting from hybridisation between ''

'' and '' Sorbus porrigentiformis''Robertson, A., Rich, T.C., Allen, A.M., Houston, L., Roberts, C.A.T., Bridle, J.R., Harris, S.A. and Hiscock, S.J., 2010. Hybridization and polyploidy as drivers of continuing evolution and speciation in Sorbus. Molecular Ecology, 19(8), pp.1675-1690.

References

Sources

eminens Endemic flora of the United Kingdom Vulnerable plants Plants described in 1957 Taxonomy articles created by Polbot {{sorbus-stub