White Willow: Encyclopedia - White Willow
White Willow
* See Golden Willow for information on the horse of that name.
The White Willow is a willow native to Europe, and western and central Asia. It is a large deciduous tree up to 20-30 m tall. The name derives from the leaves, which are paler than most other willows, due to a covering of very fine silky white hairs, particularly on the underside. The leaves are typically 5-10 cm long and 1-1.5 cm wide. The shoots in the typical species are grey-brown to green-brown. The flowers are catkins, produced in early spring.
A number of cultivars and hybrids of White Willow have been selected for forestry and horticulture use:
* The Cricket-bat Willow (Salix alba 'Caerulea') is grown as a specialist timber crop in Britain, mainly for the production of cricket bats, but also for other uses where a tough, lightweight wood that does not splinter easily, is required. It is distinguished mainly by its growth form, very fast growing with a single straight stem, and also by its slightly larger leaves (10-11 cm long, 1.5-2 cm wide) with a more blue-green colour. Its origin is unknown, but it may be a hybrid between White Willow and Crack Willow (Salix fragilis).
* The Weeping Willow (Salix × sepulcralis 'Chrysocoma', syn. Salix 'Tristis') is a hybrid between White Willow and Peking Willow (Salix babylonica, syn. Salix matsudana).
* The Golden Willow (Salix alba 'Vitellina') is a cultivar grown in gardens for its shoots, which are golden yellow for 1-2 years before turning brown. It is particularly decorative in winter; the best effect is achieved by coppicing it every 2-3 years to stimulate the production of longer young shoots with better colour. Two other similar cultivars, 'Britzensis' and 'Cardinal', have orange-red shoots.
White Willows are fast-growing, but short-lived, being susceptible to several diseases, including watermark disease caused by the bacterium Erwinia salicis (named because of the characteristic 'watermark' staining in the wood) and willow anthracnose, caused by the fungus Marssonina salicicola. These diseases can be a serious problem on trees grown for timber or ornament.
White Willow - Medicinal Uses
Hippocrates, a Greek physician for whom the Hippocratic Oath is named, wrote in the 5th century BC about a bitter powder extracted from willow bark that could ease aches and pains and reduce fevers. This remedy is also mentioned in texts from ancient Sumeria, Egypt and Assyria. Native American Indians used it for headaches, fever, sore muscles, rheumatism, and chills. The Reverend Edward Stone, a vicar from Chipping Norton in Oxfordshire England, noted in 1763 that the bark of the willow was effective in reducing a fever.
The active extract of the bark, called salicin, after the Latin name for the White willow (Salix alba), was isolated to its crystaline 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 highly acidic when in a saturated solution with water (pH = 2.4), and is called salicylic acid for that reason. This is the precursor to modern aspirin (acetylsalicylic acid).
White Willow illustration
Catkins
Category: Salicaceae
