Salix caprea is a common species of willow

Willow

Willows, sallows, and osiers form the genus Salix, around 400 species of deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions of the Northern Hemisphere...

 native to Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

 and western and central Asia

Asia

Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

.

It is a deciduous

Deciduous

Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...

 shrub

Shrub

A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...

 or small tree

Tree

A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...

, reaching a height of 8-10 m, rarely to 13 m. The leaves

Leaf

A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....

 are 3-12 cm long and from 2-8 cm wide, broader than most other willows. The flower

Flower

A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...

s are soft silky, silvery 3-7 cm long catkin

Catkin

A catkin or ament is a slim, cylindrical flower cluster, with inconspicuous or no petals, usually wind-pollinated but sometimes insect pollinated . They contain many, usually unisexual flowers, arranged closely along a central stem which is often drooping...

s, produced in early spring before the new leaves appear; the male and female catkins are on different plants (dioecious

Plant sexuality

Plant sexuality covers the wide variety of sexual reproduction systems found across the plant kingdom. This article describes morphological aspects of sexual reproduction of plants....

). The male catkins mature yellow at pollen

Pollen

Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes . Pollen grains have a hard coat that protects the sperm cells during the process of their movement from the stamens to the pistil of flowering plants or from the male cone to the...

 release, the female catkins maturing pale green. The fruit

Fruit

In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...

 is a small capsule

Capsule (fruit)

In botany a capsule is a type of simple, dry fruit produced by many species of flowering plants. A capsule is a structure composed of two or more carpels that in most cases is dehiscent, i.e. at maturity, it splits apart to release the seeds within. A few capsules are indehiscent, for example...

 5-10 mm long containing numerous minute seed

Seed

A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...

s embedded in fine cottony hairs. The seeds are very small (about 0.2 mm) with the fine hairs aiding dispersal; they require bare soil

Soil

Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...

 to germinate

Germination

Germination is the process in which a plant or fungus emerges from a seed or spore, respectively, and begins growth. The most common example of germination is the sprouting of a seedling from a seed of an angiosperm or gymnosperm. However the growth of a sporeling from a spore, for example the...

.

There are two varieties

Variety (biology)

In botanical nomenclature, variety is a taxonomic rank below that of species: as such, it gets a three-part infraspecific name....

:

• Salix caprea var. caprea. Lowland regions throughout the range. Leaves thinly hairy above, densely hairy below, 5-12 cm long; stipules persistent until autumn.
• Salix caprea var. sphacelata (Sm.) Wahlenb. (syn. S. caprea var. coaetanea Hartm.; S. coaetanea (Hartm.) Floderus). High altitudes in the mountains of central and northern Europe (Alps, Carpathians, Scotland, Scandinavia). Leaves densely silky-hairy on both sides, 3-7 cm long; stipules early deciduous.

The scientific name, and the common name Goat Willow, probably derive from the first known illustration of the species in Hieronymus Bock

Hieronymus Bock

Hieronymus Bock was a German botanist, physician, and Lutheran minister who began the transition from medieval botany to the modern scientific worldview by arranging plants by their relation or resemblance....

's 1546 Herbal

Herbal

AThe use of a or an depends on whether or not herbal is pronounced with a silent h. herbal is "a collection of descriptions of plants put together for medicinal purposes." Expressed more elaborately — it is a book containing the names and descriptions of plants, usually with information on their...

, where the plant is shown being browsed by a goat

Goat

The domestic goat is a subspecies of goat domesticated from the wild goat of southwest Asia and Eastern Europe. The goat is a member of the Bovidae family and is closely related to the sheep as both are in the goat-antelope subfamily Caprinae. There are over three hundred distinct breeds of...

. The species was historically also widely used as a browse for goats, to which Bock's illustration may refer.

Ecology

Salix caprea occurs both in wet environments, such as riverbanks and lake shores, and in drier sites, wherever bare soil becomes available due to ground disturbance.

Hybrids with several other willow species are common, notably with Salix cinerea (S. × reichardtii), Salix aurita

Salix aurita

Salix aurita is a species of willow distributed over much of Europe, and occasionally cultivated. It is a shrub to 2.5 m in height, distinguished from the similar but slightly larger Salix cinerea by its reddish petioles and young twigs. It was given its name because of the persistent...

(S. × multinervis), Salix viminalis (S. × smithiana), and Salix purpurea (S. × sordida). Populations of Salix caprea often show hybrid introgression.

Unlike almost all other willows, pure specimens of Salix caprea do not take root readily from cuttings; if a willow resembling the species does root easily, it is probably a hybrid with another species of willow.

The leaves are used as a food resource by several species of Lepidoptera, and are also commonly eaten by browsing mammal

Mammal

Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

s. Willows are very susceptible to gall inducers and the midge Rhabdophaga rosaria

Rhabdophaga rosaria

Rhabdophaga rosaria is a gall midge which forms Camellia galls or terminal rosette gall on willow species.-Description:Willows are extremely susceptible to gall induction and growth manipulation and Salix is one of the plant genera with the highest known numbers of associated galler species.The...

 forms the Camellia gall on S. caprea.

Cultivation and uses

A small number of cultivar

Cultivar

A cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...

s have been selected for garden use. The most common is S. caprea 'Kilmarnock', with stiffly pendulous shoots, forming a mop-head; it is a male clone. A similar female clone is S. caprea 'Weeping Sally'. As they do not form a leader, they are grafted

Grafting

Grafting is a horticultural technique whereby tissues from one plant are inserted into those of another so that the two sets of vascular tissues may join together. This vascular joining is called inosculation...

 on erect stems of other willows; the height of these cultivars is determined by the height at which the graft is made. Plants can also be grown from greenwood cuttings make attractive creeping mounds. Hardwood cuttings are often difficult to root.

Both tannin

Tannin

A tannin is an astringent, bitter plant polyphenolic compound that binds to and precipitates proteins and various other organic compounds including amino acids and alkaloids.The term tannin refers to the use of...

 and salicin can be extracted from Goat Willow bark. The tree is not considered a good source of timber

Timber

Timber may refer to:* Timber, a term common in the United Kingdom and Australia for wood materials * Timber, Oregon, an unincorporated community in the U.S...

 as its wood is both brittle and known to crackle violently if burned.

As with the closely related Salix discolor

Salix discolor

Salix discolor is a species of willow native to North America, one of two species commonly called Pussy Willow.It is native to the northern forests and wetlands of Canada and the northeastern contiguous United States .It is a weak-wooded deciduous shrub or...

(American Pussy Willow), it is also often grown for cut flowers. See Pussy Willow

Pussy Willow

Pussy willow is a name given to many of the smaller species of the genus Salix when their furry catkins are young in early spring...

for further cultural information, which apply to both species.