''Salix herbacea'', the dwarf willow, least willow or snowbed willow, is a species of tiny creeping

willow Willows, also called sallows and osiers, of the genus ''Salix'', comprise around 350 species (plus numerous hybrids) of typically deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions. Most species are known ...

(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 ...

) adapted to survive in harsh arctic and subarctic environments. Distributed widely in alpine and arctic environments around the

North Atlantic Ocean The Atlantic Ocean is the second largest of the world's five oceanic divisions, with an area of about . It covers approximately 17% of Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for se ...

, it is one of the smallest

woody plant A woody plant is a plant that produces wood as its structural tissue and thus has a hard stem. In cold climates, woody plants further survive winter or dry season above ground, as opposed to Herbaceous plant, herbaceous plants that die back to t ...

Distribution

''Salix herbacea'' is adapted to survive in harsh environments, and has a wide distribution on both sides of the

North Atlantic The Atlantic Ocean is the second largest of the world's five oceanic divisions, with an area of about . It covers approximately 17% of Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for ...

, in arctic northwest

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

, northern

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

Greenland Greenland is an autonomous territory in the Danish Realm, Kingdom of Denmark. It is by far the largest geographically of three constituent parts of the kingdom; the other two are metropolitan Denmark and the Faroe Islands. Citizens of Greenlan ...

, and eastern

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

, and further south on high

mountain A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher t ...

s, south to the

Pyrenees The Pyrenees are a mountain range straddling the border of France and Spain. They extend nearly from their union with the Cantabrian Mountains to Cap de Creus on the Mediterranean coast, reaching a maximum elevation of at the peak of Aneto. ...

, the northern

Apennines The Apennines or Apennine Mountains ( ; or Ἀπέννινον ὄρος; or – a singular with plural meaning; )Latin ''Apenninus'' (Greek or ) has the form of an adjective, which would be segmented ''Apenn-inus'', often used with nouns s ...

, the

Alps The Alps () are some of the highest and most extensive mountain ranges in Europe, stretching approximately across eight Alpine countries (from west to east): Monaco, France, Switzerland, Italy, Liechtenstein, Germany, Austria and Slovenia. ...

and the

Rila Rila (, ) is the highest mountain range of Bulgaria, the Balkans, Balkan Peninsula, and Southeast Europe. It is situated in southwestern Bulgaria and forms part of the Rila–Rhodope Mountains, Rhodope Massif. The highest summit is Musala at an e ...

in Europe, and the northern

Appalachian Mountains The Appalachian Mountains, often called the Appalachians, are a mountain range in eastern to northeastern North America. The term "Appalachian" refers to several different regions associated with the mountain range, and its surrounding terrain ...

in the eastern

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

. It grows in

tundra In physical geography, a tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. There are three regions and associated types of tundra: #Arctic, Arctic, Alpine tundra, Alpine, and #Antarctic ...

and rocky

moorland Moorland or moor is a type of Habitat (ecology), habitat found in upland (geology), upland areas in temperate grasslands, savannas, and shrublands and the biomes of montane grasslands and shrublands, characterised by low-growing vegetation on So ...

, usually at over elevation in the south of its range but down to sea level in the Arctic.Meikle, R. D. (1984). ''Willows and Poplars of Great Britain and Ireland''. BSBI Handbook No. 4. .Salicaceae of the Canadian Arctic Archipelago
''Salix herbacea''
/ref>

Description

The dwarf willow is one of the smallest

s in the world. It typically grows to only in height, with spreading prostrate branches, reddish brown and very sparsely hairy at first, growing just underground forming open mats. The

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

are deciduous, rounded, crenate to toothed and shiny green with paler undersides, 0.3–2 cm long and broad. Like other willows, it is

dioecious Dioecy ( ; ; adj. dioecious, ) is a characteristic of certain species that have distinct unisexual individuals, each producing either male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproduction is ...

, with male and female

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 on separate plants. As a result, the plant's appearance varies; the female catkins are red-coloured when ripe, while the male catkins are yellow-coloured. In colder

biome A biome () is a distinct geographical region with specific climate, vegetation, and animal life. It consists of a biological community that has formed in response to its physical environment and regional climate. In 1935, Tansley added the ...

s with

habitat fragmentation Habitat fragmentation describes the emergence of discontinuities (fragmentation) in an organism's preferred environment (habitat), causing population fragmentation and ecosystem decay. Causes of habitat fragmentation include geological proces ...

, geographic isolation, and heterogeneous availability of

resource ''Resource'' refers to all the materials available in our environment which are Technology, technologically accessible, Economics, economically feasible and Culture, culturally Sustainability, sustainable and help us to satisfy our needs and want ...

s, the dwarf willow often exhibits clonal propagation of genets in which

ramet A clonal colony or genet is a group of genetically identical individuals, such as plants, fungi, or bacteria, that have grown in a given location, all originating vegetatively, not sexually, from a single ancestor. In plants, an individual in ...

s are physiologically integrated and thereby share resources. Some genets of the dwarf willow in the Northern

in Italy are at least 2000 years old.

References

External links

* * {{Authority control herbacea Flora of the Arctic Flora of Europe Flora of Northern America Flora of temperate Asia Plants described in 1753 Taxa named by Carl Linnaeus