Salix viminalis

Salix viminalis
Common Osier foliage
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Rosids
Order:	Malpighiales
Family:	Salicaceae
Genus:	Salix
Species:	S. viminalis
Binomial name
Salix viminalis L.

Salix viminalis, the Common Osier or Osier, is a species of willow (Salix) native to Europe and western Asia.^[1][2][3]

Description

Salix viminalis is a multistemmed shrub growing to between 3–6 m (rarely to 10 m) tall. It has long, erect, straight branches with greenish-grey bark. The leaves long and slender, 10–25 cm long but only 0.5–2 cm broad; they are dark green above, with a silky grey-haired underside. The flowers are catkins, produced in early spring before the leaves; they are dioecious, with male and female catkins on separate plants. The male catkins are yellow and oval-shaped; the female catkins are longer and more cylindrical; they mature in early summer when the fruit capsules split open to release the numerous minute seeds.^[1][2]

Distribution and habitat

It is commonly found by streams and other wet places. The exact native range is uncertain due to extensive historical cultivation; it is certainly native from central Europe east to western Asia, but may also be native as far west as southeastern England. As a cultivated or naturalised plant, it is widespread throughout both Britain and Ireland, but only at lower altitudes. It is one of the least variable willows, but it will hybridise with several other species.^[1][2]

Uses

Along with other related willows, the flexible twigs (called "withies") are commonly used in basketry, giving rise to its alternative common name of "basket willow". In the Chilean village of Chimbarongo, it is used to fashion the renowned baskets.

Another increasing use is in energy forestry,^[1] effluent treatment, in wastewater gardens, and in Cadmium phytoremediation water purification.^[3]

Salix viminalis is a known hyperaccumulator of Cadmium, Chromium, Lead, Mercury, Zinc, Petroleum hydrocarbons, Organic solvents, MTBE, TCE and by-products, Selenium, Silver, Uranium, Zinc,^[4][5] and Potassium ferrocyanide (tried on S. babylonica L.),^[6] and as such is a prime candidate for phytoremediation. For more information, see the list of hyperaccumulators.

References

1. ^ ^{a b c d} Meikle, R. D. (1984). Willows and Poplars of Great Britain and Ireland. BSBI Handbook No. 4. ISBN 0-901158-07-0.
2. ^ ^{a b c} Rushforth, K. (1999). Trees of Britain and Europe. Collins ISBN 0-00-220013-9.
3. ^ ^{a b} Perttu, K. L. and Kowalik, P. J. (1997). Salix vegetation filters for purification of waters and soils. Biomass and Bioenergy, Volume 12, Issue 1, 1997, Pages 9-19. Elsevier Science Ltd.
4. ^ Phytoremediation. By McCutcheon & Schnoor. 2003, New Jersey, John Wiley & Sons, page 19.
5. ^ Enhancing Phytoextraction: The Effect of Chemical Soil Manipulation on Mobility, Plant Accumulation, and Leaching of Heavy Metals. By Ulrich Schmidt. In J. Environ. Qual. 32:1939-1954 (2003).
6. ^ The potential for phytoremediation of iron cyanide complex by Willows. By X.Z. Yu, P.H. Zhou and Y.M. Yang. In Ecotoxicology 2006.