Drugs & Medication

Willows
Weeping Willow
Scientific classification
Kingdom: Plantae   Division: Magnoliophyta   Class: Magnoliopsida   Order: Malpighiales   Family: Salicaceae   Genus: Salix L.
Species
About 350, including: Salix acutifolia - Violet Willow Salix alaxensis - Alaska Willow Salix alba - White Willow Salix alpina - Alpine Willow Salix amygdaloides - Peachleaf Willow Salix arbuscula - Mountain Willow Salix arbusculoides - Littletree Willow Salix arctica - Arctic Willow Salix atrocinerea Salix aurita - Eared Willow Salix babylonica - Peking Willow Salix bakko Salix barrattiana - Barratt's Willow Salix bebbiana - Beaked Willow Salix boothii - Booth Willow Salix bouffordii Salix brachycarpa - Barren-ground Willow Salix cacuminis Salix canariensis Salix candida - Sage Willow Salix caprea - Goat Willow Salix caroliniana - Coastal Plain Willow Salix chaenomeloides Salix chilensis Salix cinerea - Grey Sallow Salix cordata Salix daphnoides Salix discolor - Pussy Willow Salix eastwoodiae - Eastwood's Willow Salix eleagnos Salix eriocarpa Salix eriocephala - Heartleaf Willow Salix exigua - Sandbar Willow Salix foetida Salix fragilis - Crack Willow Salix futura Salix geyeriana Salix gilgiana Salix glauca Salix gooddingii - Goodding Willow Salix gracilistyla Salix hainanica - Hainan Willow Salix helvetica - Swiss Willow Salix herbacea - Dwarf Willow Salix hookeriana - Hooker's Willow Salix hultenii Salix humboldtiana - Chile Willow Salix humilis - Upland Willow Salix integra Salix interior Salix japonica Salix jessoensis Salix koriyanagi Salix kusanoi Salix lanata - Woolly Willow Salix lapponum - Downy Willow Salix lasiandra - Pacific Willow Salix lasiolepsis - Arroyo Willow Salix lucida - Shining Willow Salix magnifica Salix matsudana - Chinese Willow Salix miyabeana Salix mucronata Salix myrtilloides - Swamp Willow Salix myrsinifolia - Dark-leaved Willow Salix myrsinites - Whortle-leaved Willow Salix nakamurana Salix nigra - Black Willow Salix pedicellaris - Bog Willow Salix pentandra - Bay Willow Salix petiolaris - Slender Willow Salix phylicifolia - Tea-leaved Willow Salix planifolia- Planeleaf Willow Salix polaris - Polar Willow Salix pseudo-argentea Salix purpurea - Purple Willow Salix pyrifolia - Balsam Willow Salix reinii Salix repens - Creeping Willow Salix reticulata - Net-leaved Willow Salix retusa Salix rorida Salix rosmarinifolia - Rosemary-leaved Willow Salix rupifraga Salix salicicola Salix schwerinii Salix scouleriana - Scouler's Willow Salix sericea - Silky Willow Salix serissaefolia Salix serissima - Autumn Willow Salix shiraii Salix sieboldiana Salix sitchensis Salix subfragilis Salix subopposita Salix taraikensis Salix tetrasperma Salix thorelii Salix triandra - Almond Willow Salix udensis Salix viminalis - Common Osier Salix vulpina Salix waldsteiniana Salix wallichiana Salix yezoalpina Salix yoshinoi

The willows are deciduous trees and shrubs in the genus Salix, part of the willow family Salicaceae.

There are about 350 species in this genus worldwide, found primarily on moist soils in cooler zones in the Northern Hemisphere. The leaves are deciduous, often elongate but round to oval in a few species, and with a serrated margin. Willows are dioecious with male and female flowers appearing as catkins on different plants; the catkins are produced early in the spring, often before the leaves or as the new leaves open. The fruit is a small capsule containing numerous tiny (0.1 mm) seeds embedded in white down, which assists wind dispersal of the seeds. Willows are very cross-fertile and numerous hybrids are known, both naturally occurring and in cultivation.

Some smaller species may also be known by the common names osier and sallow; the latter name is derived from the same root as the Latin salix.

Some willows, particularly arctic and alpine species, are very small; the Dwarf Willow (Salix herbacea) rarely exceeds 6 cm in height, though spreading widely across the ground.

The Weeping Willow, very widely planted as an ornamental tree, is a cultivar, Salix × sepulcralis 'Chrysocoma', derived from a hybrid between the Chinese Peking Willow and the European White Willow.

Almost all willows take root very readily from cuttings or where broken branches lie on the ground. There are a few exceptions, including the Goat Willow and Peachleaf Willow. One famous example of such growth from cuttings involves the poet Alexander Pope, who begged a twig from a parcel tied with twigs sent from Spain to Lady Suffolk. This twig was planted and thrived, and legend has it that all of England's Weeping Willows are descended from this first one [1]. Willows are used as food plants by the larvae of some Lepidoptera species - see list of Lepidoptera which feed on Willows.

Uses

Medicinal uses

The bark of the willow tree has been mentioned in ancient texts from Assyria, Sumer and Egypt as a remedy for aches and fever, and the Greek physician Hippocrates wrote about its medicinal properties in the 5th century BC. Native Americans across the American continent relied on it as a staple of their medical treatments.

The active extract of the bark, called salicin, was isolated to its crystalline form in 1828 by Henri Leroux, a French pharmacist, and Raffaele Piria, an Italian chemist, who then succeeded in separating out the acid in its pure state. Salicin is acidic when in a saturated solution in water (pH = 2.4), and is called salicylic acid for that reason.

In 1897 Felix Hoffmann created a synthetically altered version of salicin (in his case derived from the Spiraea plant), which caused less digestive upset than pure salicylic acid. The new drug, formally Acetylsalicylic acid, was named aspirin by Hoffmann's employer Bayer AG. This gave rise to the hugely important class of drugs known as non-steroidal anti-inflammatory drugs (NSAIDs).

Other uses

• Agroforestry
  Basket weaving
  Biofiltration
  Biomass energy (bioenergy)
  Box, Veneer
  Charcoal
  Constructed wetlands
  Cricket bats
  Cradle boards
  Chairs & furniture
  Dolls, toys, whistles
  Ecological wastewater treatment systems
  Energy forestry
  As part of the four species used on the Jewish holiday of Sukkot.
  Fibre plants
• Fish traps
• Flutes
  Hedges
  Land reclamation
  Landscaping
  Living Willow Sculpture
  Paper
  Phytoremediation
  Poles, turnery, tool handles
  Rope and string
  Streambank stabilisation (bioengineering)
  Slope stabilisation
  Soil erosion control
  Soil building
  Soil reclamation
  Shelterbelt & windbreak
  Sweat lodges
• Tannin
• Wands, brooms
  Wattle fences
  Wattle and daub
  Wildlife habitat

External links and references

• Newsholme, C. (1992). Willows: The Genus Salix. ISBN 0-88192-565-9
• Warren-Wren, S.C. (1992). The Complete Book of Willows. ISBN 0-498-01262-X
• Refererence for the story concerning Alexander Pope Extract from the Every day book by William Hone, (1826) quoting "Martyn" and the Saint James's Chronicle (1801).
• Salix alba at plants for a future
• Salix purpurea at plants for a future
• 1911 Encyclopaedia Britannica
• Salix caroliniana images at bioimages.vanderbilt.edu
• Salix nigra images at bioimages.vanderbilt.edu
• Salix humboldtiana or Chilean willow images