Definitions

willow

willow

[wil-oh]
willow, common name for some members of the Salicaceae, a family of deciduous trees and shrubs of worldwide distribution, especially abundant from north temperate to arctic areas. The family consists of two genera, Salix and Populus, both of which are propagated easily by cuttings, grow rapidly, and characteristically bear male and female flowers in catkins on separate plants. Many plants of the narrower-leaved willow genus (Salix) flourish in cold, wet ground; willows grow farther north than any other woody angiosperm (flowering plant). The poplars (genus Populus) usually have heart-shaped or ovate leaves; they include the cottonwoods, aspens, and many species specifically named poplar. The cottonwoods (sometimes also called poplars) characteristically have seeds that are covered with fibrous coats so that when they are released at maturity they clump together in cottony balls. Cottonwoods were a welcome sight to the pioneers pushing westward, for they marked the streams in the otherwise treeless Great Plains. Some of the poplars, especially the aspens, have flattened leaf stalks that permit the pendulous leaves to quiver in the slightest breeze (hence the name quaking aspen). The quaking, or golden, aspen is a common deciduous tree of the mountains of the W United States; it is often the first tree to reforest burned-over woodlands. Because the lumber of this family is so soft it finds little use except for paper pulp (mostly the poplars), for charcoal, and especially in basketry and wickerwork (mostly the willows). The bushes and their twigs used in basketry are often called osiers. Willow buds and bark have also been used medicinally; the chemical predecessor of aspirin was originally isolated from the bark of a willow. The trees are valuable in erosion control along riverbanks because of their rapid growth. Economically the family is most noted for its many species planted as ornamentals, e.g., the Lombardy and the silver, or white, poplars, now naturalized in North America from Eurasia; the weeping willow, indigenous to China; and the pussy willow of North America. Populus gileadensis, an ancient horticultural species whose original form is unknown, is one of the plants called balm of Gilead. Yellow poplar is a name sometimes used for the unrelated tulip tree of the magnolia family. Willows are classified in the division Magnoliophyta, class Magnoliopsida, order Salicales, family Salicaceae.

Weeping willow (Salix babylonica).

Any shrub or tree of the genus Salix, family Salicaceae, native mostly to northern temperate regions, and common in lowland and marshy areas. Willows are valued as ornamentals and for their shade, erosion control, and timber. Certain species yield salicin, the source of salicylic acid used in pain relievers. All species have alternate, usually narrow leaves, catkins, and seeds with long, silky hairs. Pussy willows, the male form of several shrubby species, have woolly catkins that form before the leaves appear and are considered one of the first signs of spring. Weeping willows have long drooping branches and leaves. Several species grow as small matted woody plants on the tundra.

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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. Most species are known as willow, but some narrow-leaved shrub species are called osier, and some broader-leaved species are called sallow (the latter name is derived from the Latin word salix, willow). Some willows (particularly arctic and alpine species), are low-growing or creeping shrubs; for example the dwarf willow (Salix herbacea) rarely exceeds 6 cm in height, though spreading widely across the ground.

Willows are very cross-fertile and numerous hybrids occur, both naturally and in cultivation. A well known example is the weeping willow (Salix × sepulcralis), very widely planted as an ornamental tree, which is a hybrid of a Chinese species and a European species – Peking willow and white willow.

Description

The willows all have abundant watery sap, bark which is heavily charged with salicylic acid, soft, usually pliant, tough wood, slender branches and large, fibrous, often stoloniferous roots. The roots are remarkable for their toughness, size, and tenacity of life, and roots readily grow from aerial parts of the plant.

The leaves are typically elongated but may also be round to oval, frequently with a serrated margin. All the buds are lateral; no absolutely terminal bud is ever formed. The buds are covered by a single scale, enclosing at its base two minute opposite buds, alternately arranged, with two, small, scale-like, fugacious, opposite leaves. The leaves are alternate, except the first pair which fall when about an inch long. They are simple, feather-veined, and typically linear-lanceolate. Usually they are serrate, rounded at base, acute or acuminate. The leaf petioles are short, the stipules often very conspicuous, looking like tiny round leaves and sometimes remaining for half the summer. On some species, however, they are small, inconspicuous, and fugacious (soon falling). In color the leaves show a great variety of greens, ranging from yellowish to bluish.

Flowers

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 staminate (male) flowers are without either calyx or corolla; they consist simply of stamens, varying in number from two to ten, accompanied by a nectariferous gland and inserted on the base of a scale which is itself borne on the rachis of a drooping raceme called a catkin, or ament. This scale is oval and entire and very hairy. The anthers are rose colored in the bud but orange or purple after the flower opens, they are two-celled and the cells open longitudinally. The filaments are threadlike, usually pale yellow, and often hairy.

The pistillate (female) flowers are also without calyx or corolla; and consist of a single ovary accompanied by a small flat nectar gland and inserted on the base of a scale which is likewise borne on the rachis of a catkin. The ovary is one-celled, the style two-lobed, and the ovules numerous.

Fruit

The fruit is a small, one-celled, two-valved, cylindrical beaked capsule containing numerous tiny (0.1 mm) seeds. The seeds are furnished with long, silky, white hairs, which allow the fruit to be widely dispersed by the wind.

Cultivation

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.

Willows are often planted on the borders of streams so that their interlacing roots may protect the bank against the action of the water. Frequently the roots are much larger than the stem which grows from them.

Ecological issues

Willows are used as food plants by the larvae of some Lepidoptera species - see list of Lepidoptera that feed on willows.

A number of willow species were widely planted in Australia, notably as erosion control measures along watercourses. They are now regarded as an invasive weed and many catchment management authorities are removing them to be replaced with native trees.

Uses

Medicinal uses

The leaves and bark of the willow tree have been mentioned in ancient texts from Assyria, Sumer and Egypt as a remedy for aches and fever, and the Ancient 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. This is because they contain salicylic acid, the precursor to aspirin.

In 1763 its medicinal properties were observed by the Reverend Edward Stone in England. He notified the Royal Society who published his findings. 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

As a plant : Agroforestry, biofiltration, constructed wetlands, ecological wastewater treatment systems, hedges, land reclamation, landscaping, phytoremediation, streambank stabilisation (bioengineering), slope stabilisation, soil erosion control, shelterbelt & windbreak, soil building, soil reclamation, tree bog compost toilet, wildlife habitat Agriculture : Willow bark contains auxins: plant growth hormones, especially those used for rooting new cuttings. The bark can even be used to make a simple extract that will promote cutting growth. Apiculture : Willow trees produce a modest amount of nectar that bees can make honey from, and are especially valued as a source of pollen for bees. Energy source : Charcoal, energy forestry such as the Willow Biomass Project Wood : Boxes, brooms, cricket bats (grown from certain strains of white willow), cradle boards, chairs and other furniture, dolls, flutes, poles, sweat lodges, toys, turnery, tool handles, veneer, wands, whistles Wicker (often from osiers): Basket weaving, fish traps, wattle fences, wattle and daub Other wood-derived products: Fibre plants, paper, rope and string, tannin Art: Willow charcoal (for drawing), living sculpture Religion : As one of the "Four Species" used in a ceremony on the Jewish holiday of Sukkot. Also the willow is one of the nine sacred trees mentioned in wicca and witchcraft, with several magical uses.

Willow in human culture

The willow is a famous subject in many East Asian nations' cultures particularly painting (pen and ink) in China and Japan.

Gisaeng Hongrang, who lived in the middle of the Joseon period, wrote:

like willow I will be the willow on your bedside.
Hongrang wrote this poem by the willow in the rain in the evening which she gave to her parting lover . In English folklore, a willow tree is believed to be quite sinister, capable of uprooting itself and stalking travellers.

Willow trees are quite prevalent in folklore and myths .

In literature

Hans Christian Andersen wrote a story called Under The Willow Tree (1853) in which children ask questions of a tree they call 'willow-father', paired with another entity called 'elder-mother'.

Green Willow is a Japanese ghost story in which a young samurai falls in love with a woman called Green Willow who has a close spiritual connection with a willow tree. The Willow Wife is another, not dissimilar tale. Wisdom of the Willow Tree is an Osage Nation story in which a young man seeks answers from a Willow tree, addressing the tree in conversation as 'Grandfather'.

In JK Rowling's Harry Potter and the Chamber of Secrets, and Harry Potter and the Prisoner of Azkaban, there is an ancient tree on the school grounds of Hogwarts called the "Whomping Willow". It is provided as a hiding spot of a secret passageway that Professor Remus Lupin roamed through every full moon when he began his transformation into a werewolf.

Also, in William Shakespeare's Hamlet, the character Ophelia climbed a Willow tree when a branch broke and dropped her into the river below where she drowned. In Shakespeare's "Twelfth Night", Viola (disguised as Cesario) tells Olivia "Make me a willow-cabin at your gate/ And call upon my soul within the house." The willow here being an emblem of forsaken love.

Pictures

See also

External links

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

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