Salix alba

Willows stand out from all other trees through features peculiar to their genus. Sallx, which gives its name to the family Salicaceae. But within this genus there are many species, varieties and hybrids, which baffle the experts, and the willows range in size from tall trees through shrubs to prostrate forms that creep over the surface of the ground Four common tree forms are described here.

Willow buds have several scales but only one bud scale can be seen on the outer surface; this is a useful feature for identification, since only the plane with its distinctive conical bud {see Figure 48) shows this feature too. The buds are alternately set but vary considerably in size and shape, as our drawings show.

Willow leaves are simple In outline, never lobed or compound. Their shape varies, according to species, from broad ovals through ellipses to long, narrow lanceolate.

With rare exceptions in a few ornamental kinds, willow trees are wholly male or wholly female. In their early stages the familiar "pussy willow' outline of both sexes look much alike, and a close look is needed to say which is which Liter. the stamens.

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Winter twig of White willow (life size) and a single leaf bud (X4). Note white down on bud.

with their golden pollen, become obvious on the male tree. Catkins on female trees remain whitish green in colour, and eventually become downy as their seed pods open to release tiny seeds, each tipped with while hairs. Most willows flower in March, Just before their leaves open, but a few delay flowering until May, Wind is the main agent for pollination, but nectaries are present and some pollen is carried from flower to flower by insects: bees seek out willows as the earliest source of nectar on warm spring days.

In detail, each male catkin {see Figure 93) consists of a dense duster of small, very simple flowers. Each single flower is made up of a scale that is densely clad in white hairs, giving it a soft outline. Two stamens only spring up from the base of this scale, in contrast to the larger numbers found in the nearly-related poplars.

Female catkins (Figure 93) are also crowded, though each separate flower can be singled out Each flower has a single bract and a long slender pistil, topped by two often bi-lobed stigmas. After pollination, the ovary develops into a seed pod which splits from the top down to release numerous fine seeds, bearing the white hairs that carry them on the wind. Willow seed is short-lived and only those seeds that alight on damp, bare earth in midsummer are likely to produce seedlings. This explains why wild willows are nearly always seen along watersides, where moist mud is available, or else in places like gravel beds or rock crevices, where a seed can be blown into a damp, shaded spot Once established they will thrive in any normal soiL

Willow seedlings bear first two tiny round seed-leaves, then two little true leaves, oppositely set. then two larger Leaves, also opposite; the alternative leaf arrangement then follows.

Willow wood is pale brown in colour, and exceptionally light in weight, though remarkably tough. In the slender twig form, or when split into thin bands, it is very pliable in the moist state, but sets into a firm shape as soon as it dries and seasons. For these reasons it is the first choice for basket making. Other uses include cricket hats and artificial limbs, and, in the past shoulder-yokes for dairy-maids, so that they could carry two heavy pails of milk at one time.

The White willow. Saiix alba, is the commonest of the timber tree species. It can be identified by the slender outline of its leaves, which are lanceolate (see Figure 90), They have a slighdy toothed edge and are smooth on both surfaces. They are silvery-white below and greyish-green above; this whiteness, which gives the tree its name, is obvious and fascinating to watch when the wind stirs the foliage, as our photograph shows.

White willow is most often seen as a waterside tree in the English Midlands and southern counties, though its range extends to Scodand, Most of the quaint pollarded willows belong to this species. They used to be cut over at intervals, and the slender shoots that arose were used for rough baskets and hurdle making.

The weeping willows seen in gardens belong to a variety of this species, Salix alba 'Tristis,' or to a hybrid with the true Weeping willow S. babylonica. This latter species had been introduced from China, and is featured on the willow-pattern plate, but it is not hardy in Britain. The hybrid, Salix x chrysocoma. is the commoner form, male, long-pendulous and holding its leaves still green into late autumn.

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