''Salix euxina'', the eastern crack-willow, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

in the willow family

Salicaceae The Salicaceae are the willow family of flowering plants. The traditional family (Salicaceae ''sensu stricto'') includes the willows, poplars. Genetic studies summarized by the Angiosperm Phylogeny Group (APG) have greatly expanded the circumsc ...

, native from Turkey to the Caucasus. It was first described by I. V. Belyaeva in 2009. It is one of the parents of the common crack-willow, ''Salix'' × ''fragilis''.

Description

''Salix euxina'' is a tree that can reach 15–20 m high with a trunk diameter of up to 1 m. It has a wide crown, and old trees develop deeply fissured bark on their trunks. The olive green branchlets are hairless (glabrous) and very brittle at the base, so that branches easily break off. These are able to root and propagate the species. The leaves are pale green and glabrous. They have

stoma In botany, a stoma (: stomata, from Greek language, Greek ''στόμα'', "mouth"), also called a stomate (: stomates), is a pore found in the Epidermis (botany), epidermis of leaves, stems, and other organs, that controls the rate of gas exc ...

ta only on the undersurface. The

catkin A catkin or ament is a slim, cylindrical flower cluster (a spike), with inconspicuous or no petals, usually wind- pollinated ( anemophilous) but sometimes insect-pollinated (as in '' Salix''). It contains many, usually unisexual flowers, arra ...

s are relatively thick with somewhat densely clustered flowers. ''Salix'' × ''fragilis'', the hybrid between ''Salix euxina'' and ''

Salix alba ''Salix alba'', the white willow, is a species of willow native to Europe and western and Central Asia.Meikle, R. D. (1984). ''Willows and Poplars of Great Britain and Ireland''. BSBI Handbook No. 4. .Rushforth, K. (1999). ''Trees of Britain an ...

'', has hairs on its branches and branchlets, stomata on both surfaces of its leaves, and slender, more loosely flowered catkins.

Taxonomy

In 1753,

Carl Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

described the species ''Salix fragilis''. From at least the 1920s, botanists applied Linnaeus's name "''Salix fragilis''" both to a pure species and to its hybrid with ''

''. In 2009, the Nomenclature Committee for Vascular Plants decided to conserve the name "''Salix fragilis''" for the hybrid, and Irina V. Belyaeva then described the previously unnamed parent species as ''Salix euxina''. The epithet ''euxina'' refers to the distribution of the species around the

Black Sea The Black Sea is a marginal sea, marginal Mediterranean sea (oceanography), mediterranean sea lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bound ...

, known as () in

Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

Distribution and habitat

''Salix euxina'' is native to a narrow region around the east of the

, including northern

Turkey Turkey, officially the Republic of Türkiye, is a country mainly located in Anatolia in West Asia, with a relatively small part called East Thrace in Southeast Europe. It borders the Black Sea to the north; Georgia (country), Georgia, Armen ...

, the

North Caucasus The North Caucasus, or Ciscaucasia, is a subregion in Eastern Europe governed by Russia. It constitutes the northern part of the wider Caucasus region, which separates Europe and Asia. The North Caucasus is bordered by the Sea of Azov and the B ...

and the Transcaucasus, where it is found beside mountain streams. It has been introduced into parts of Europe (Belgium, European Russia, Great Britain and the Netherlands) and Canada (

Ontario Ontario is the southernmost Provinces and territories of Canada, province of Canada. Located in Central Canada, Ontario is the Population of Canada by province and territory, country's most populous province. As of the 2021 Canadian census, it ...

and

Quebec Quebec is Canada's List of Canadian provinces and territories by area, largest province by area. Located in Central Canada, the province shares borders with the provinces of Ontario to the west, Newfoundland and Labrador to the northeast, ...

). In Europe, it is much less common than the hybrid ''S. fragilis'', making up only around 10% of all specimens.

Cultivation

The name "''Salix fragilis''" was applied in cultivation to plants now recognized as either ''S.'' × ''fragilis'', ''S. alba'' or ''S. euxina''. One cultivar identified as ''S. euxina'' is 'Bullata', popular as an ornamental tree in Europe. It has a short trunk and a very dense globe-shaped crown.

References

{{taxonbar, from1=Q18119933 euxina Flora of Turkey Flora of the Caucasus Plants described in 2009