Salix caprea

Taxobox
name = "Salix caprea"
status = LR/lc

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image_width = 240px
image_caption = Goat Willow male catkins
regnum = Plantae
divisio = Magnoliophyta
classis = Magnoliopsida
ordo = Malpighiales
familia = Salicaceae
genus = "Salix"
species = "S. caprea"
binomial = "Salix caprea"
binomial_authority = L.

"Salix caprea" (Goat Willow, also known as the Pussy Willow or Great Sallow), is a common 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 4. ISBN 0-901158-07-0.]

It is a deciduous shrub or small tree, reaching a height of 6-12 m, rarely to 20 m. The leaves are 3-12 cm long and from 2-8 cm wide, broader than most other willows. The flowers are soft silky, silvery 3-7 cm long catkins, produced in early spring before the new leaves appear; the male and female catkins are on different plants (dioecious). The male catkins mature yellow at pollen release, the female catkins maturing pale green. The fruit is a small capsule 5-10 mm long containing numerous minute seeds embedded in fine cottony hairs. The seeds are very small (about 0.2 mm) with the fine hairs aiding dispersal; they require bare soil to germinate.Rushforth, K. (1999). "Trees of Britain and Europe". Collins. ISBN 0-00-220013-9.]

There are two varieties:
*"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's 1546 Herbal, where the plant is shown being browsed by a goat. The species was historically also widely used as a browse for goats, to which Bock's illustration may refer.Bean, W. J. (1980). "Trees and Shrubs Hardy in the British Isles". ISBN 0-7195-2428-8.]

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" ("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 mammals.

Cultivation and uses

A small number of cultivars 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 root from cuttings, they are grafted on erect stems of other willows; the height of these cultivars is determined by the height at which the graft is made.

Both tannin and salicin can be extracted from Goat Willow bark. The tree is not considered a good source of timber as its wood is both brittle and known to crackle violently if burned.

As with the closely related "Salix discolor" (American Pussy Willow), it is also often grown for cut flowers. See Pussy Willow for further cultural information and uses, which apply to both species.

References