''Salix repens'', the creeping willow, is a small, shrubby species of

willow Willows, also called sallows and osiers, from the genus ''Salix'', comprise around 400 speciesMabberley, D.J. 1997. The Plant Book, Cambridge University Press #2: Cambridge. of typically deciduous trees and shrubs, found primarily on moist ...

in the family

Salicaceae The Salicaceae is the willow family of flowering plants. The traditional family (Salicaceae ''sensu stricto'') included the willows, poplar, aspen, and cottonwoods. Genetic studies summarized by the Angiosperm Phylogeny Group (APG) have greatly ...

, growing up to 1.5metres in height. Found amongst sand dunes and heathlands, it is a polymorphic species, with a wide range of variants. In the UK, at least, these range from small, prostrate, hairless plants at one end of the spectrum to taller, erect or ascending silky-leaved shrubs at the other. This wide variation in form has resulted in numerous

synonyms A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are ...

Distribution

The plant has a Eurosiberian Boreo-temperate range, and is widely distributed around the coasts of western and northern Europe. In the UK, the prostrate forms (ssp. ''argentea'' and ssp. ''repens'') are characteristically found on

sand dune A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill. An area with dunes is called a dune system or a dune complex. A large dune complex is called a dune field, while broad, f ...

s, growing close to the water table in dune slacks, as well as in coastal heaths and

acid grassland Acid grassland is a nutrient-poor habitat characterised by grassy tussocks and bare ground. Habitat The vegetation is dominated by grasses and herbaceous plants, growing on soils deficient in lime (calcium). These may be found on acid sedimentar ...

, as well as being found further inland on

heath A heath () is a shrubland habitat found mainly on free-draining infertile, acidic soils and characterised by open, low-growing woody vegetation. Moorland is generally related to high-ground heaths with—especially in Great Britain—a cooler ...

s and moorland. The erect form (var. ''fusca'') occurs in

fen A fen is a type of peat-accumulating wetland fed by mineral-rich ground or surface water. It is one of the main types of wetlands along with marshes, swamps, and bogs. Bogs and fens, both peat-forming ecosystems, are also known as mires. T ...

s. The species becomes more confined to moist or wet habitats in the southern and eastern parts of its UK range, and has been recorded from sea level up to (in

East Perthshire East (or Eastern) Perthshire was a county constituency of the House of Commons of the Parliament of the United Kingdom from 1885 to 1918. It elected one Member of Parliament (MP) by the first past the post voting system. Boundaries The con ...

Ecology

Dunes containing ''Salix repens'' are recognised as being of ecological importance by the

EU Habitats Directive The Habitats Directive (more formally known as Council Directive 92/43/EEC on the Conservation of natural habitats and of wild fauna and flora) is a directive adopted by the European Community in 1992 as a response to the Berne Convention. The E ...

. Over 132

Natura 2000 Natura 2000 is a network of nature protection areas in the territory of the European Union. It is made up of Special Areas of Conservation and Special Protection Areas designated under the Habitats Directive and the Birds Directive, respectiv ...

sites are designated for this habitat type. As the water table lowers within the slack, these Salix-dominated habitats (termed Salicion arenariae) may develop either into mesophilous (neither wet nor dry), or

xerophilous A xerophile () is an extremophilic organism that can grow and reproduce in conditions with a low availability of water, also known as water activity. Water activity (aw) is measured as the humidity above a substance relative to the humidity above p ...

(dry) communities. The former may contain species such as '' Pyrola rotundifolia'', '' Viola canina'' and ''

Monotropa hypopitys ''Monotropa hypopitys'', the so-called Dutchman's pipe, false beech-drops, pinesap, or yellow bird's-nest, is a herbaceous perennial plant, formerly classified in the families Monotropaceae or Pyrolaceae, but now included within the subfamily Mon ...

''; the latter containing ''

Carlina vulgaris ''Carlina vulgaris'', the carline thistle, is a plant species of the genus ''Carlina ''Carlina'' is a genus of flowering plants in the family Asteraceae. It is distributed from Madeira and the Canary Islands across Europe and northern Africa to ...

'' and ''

Thalictrum minus ''Thalictrum minus'', known as lesser meadow-rue, is a perennial herb in the family Ranunculaceae that is native to Europe, Northwest Africa, Yemen, Ethiopia, South Africa, Southwest Asia, and Siberia. It grows on sand dunes, shingle, coas ...

''. ''Salix repens'' provides shelter to other species of plant and animal. Its soft, fluffy seed hairs provide nesting material for

songbird A songbird is a bird belonging to the suborder Passeri of the perching birds ( Passeriformes). Another name that is sometimes seen as the scientific or vernacular name is Oscines, from Latin ''oscen'', "songbird". The Passeriformes contains 50 ...

s, whilst in autumn there is often a rich assemblage of unusual

fungus A fungus (plural, : fungi or funguses) is any member of the group of Eukaryote, eukaryotic organisms that includes microorganisms such as yeasts and Mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified ...

species growing in its vicinity. Should the dune slack that the plant inhabits become inundated by an advancing dune, it is able to adapt and change its growth form from erect to prostrate. Losing its erect habit, the plant is able to creep horizontally along the front of the advancing dune and survive the changing conditions. Studies have shown that

mycorrhizal A mycorrhiza (from Greek μύκης ', "fungus", and ῥίζα ', "root"; pl. mycorrhizae, mycorrhiza or mycorrhizas) is a symbiotic association between a fungus and a plant. The term mycorrhiza refers to the role of the fungus in the plan ...

fungal associations may assist ''Salix repens'' in expanding the ecological niches it can occupy.

Hybrids

Creeping willow may hybridise with other ''Salix'' species, typically including goat willow ('' S. caprea'') and downy willow ('' S. lapponum''). One especially rare hybrid (S. x angusensis) was discovered on Ainsdale Nature Reserve,

Lancashire Lancashire ( , ; abbreviated Lancs) is the name of a Historic counties of England, historic county, Ceremonial County, ceremonial county, and non-metropolitan county in North West England. The boundaries of these three areas differ significa ...

in 1993. It is a hybrid between three Salix species: ''S. cinerea'' ssp. ''oleifolia'' x ''S. repens'' var. ''argentea'' X ''S. viminalis''.

References

External links

* * {{Taxonbar, from=Q28141 Flora of Europe

repens ''Eprius'' is a genus of skipper butterflies in the family Hesperiidae. Species *''Eprius repens'' Evans, 1955 *''Eprius repta'' Evans, 1955 *''Eprius veleda ''Eprius'' is a genus of skipper butterflies in the family Hesperiidae. Species ...

Plants described in 1753 Taxa named by Carl Linnaeus