''Salix repens'', the creeping willow, is a small, shrubby species of willow in the family Salicaceae, 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 all ...

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, fl ...

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 heaths and

moorland Moorland or moor is a type of habitat found in upland areas in temperate grasslands, savannas, and shrublands and montane grasslands and shrublands biomes, characterised by low-growing vegetation on acidic soils. Moorland, nowadays, generally ...

. The erect form (var. ''fusca'') occurs in fens. 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).

Ecology

Dunes containing ''Salix repens'' are recognised as being of ecological importance by the EU Habitats Directive. 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, respectively ...

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 (dry) communities. The former may contain species such as '' Pyrola rotundifolia'', '' Viola canina'' and '' Monotropa hypopitys''; the latter containing '' Carlina vulgaris'' 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 songbirds, whilst in autumn there is often a rich assemblage of unusual fungus 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 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 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