Willow (Supposed To Be From A. S. Wilig Pliancy), the name of shrubs or trees of the genus salix (the ancient Latin name). Some willows are in England, and to some extent in our nurseries, called sallows (A. S. sal or soel, a strap or tie), in French saule. This genus and the poplar (populus) make up the family salicacece. The willows vary in size from alpine species an inch or two high to trees of 50 to 80 ft.; they have generally lithe and slender branches; the leaves, usually long and pointed, are alternate, entire or serrate, with deciduous or persistent and often very conspicuous stipules. The flowers are dioecious, in cylindrical, often silky catkins, appearing before or with the leaves; the scales in both kinds of catkins entire; the sterile flowers have two (rarely three to ten) stamens, with one or two small glands at the base; the pistillate flowers have a single sessile or stalked ovary with a gland at its base; stigmas two, often two-lobed; the one-celled ovary ripening into a conical capsule opening by two valves, and liberating several small, silky-tufted seeds. - The willows are widely distributed from the tropics to the arctic regions, ascending mountains to the limit of vegetation, but in low countries chiefly inhabiting wet localities; they are not found in Australia. The number of species is very doubtful, as few genera present so many difficulties to the botanist; the leaves vary in the same species, and often do not appear until after the flowers, and the staminate and pistillate flowers must be gathered before the leaves appear or when these are quite young, and later specimens must be taken from the same plants with mature leaves and fruit; hence in most cases four specimens are required to represent a species, and as a consequence herbaria usually present a confused lot of incomplete specimens; besides these difficulties, the same species grown upon mountains appears different in the lowlands, and it is said that the species hybridize in the wild state to produce intermediate forms.. Only the few important species will be mentioned here, and these are sufficiently well defined; the majority are of interest only to the botanist.
Even in the limited territory of Great Britain, there is much disagreement as to the number of species, some botanists making 58, while others reduce the number to 15. Prof. Andersson of Stockholm, Sweden, who has given special attention to the willows, described the North American species in a memoir published in the "Proceedings of the* American Academy of Arts and Sciences" (1858); he enumerates 59 species, of which only 10 are peculiar to America; 12 are identical with European species, and a part of them introduced; the remainder are nearly identical with or analogous to those of Europe or of European types. The trees have a remarkably rapid growth; some species are very ornamental, while others are planted for their usefulness as wind-breaks and to resist the encroachments of streams; the roots are large and abundant, and in moist places run to a great distance and bind the soil with their numerous fibres; they grow readily from cuttings, which is the usual method of propagation, except for some ornamental varieties, which are grafted. The bark, smooth and often shining, is tough, and is used for matting, cordage, fishing nets, and similar uses in northern countries; and in times of scarcity in Norway and Sweden it is kiln-dried and ground to mix with oatmeal.
The bark in all is bitter, from the principle salicine, which is more abundant in some species than in others; this is a white crystallizable neutral substance, with the tonic properties of the bark; it has been used as a substitute for quinine, and also to adulterate that product. The bark is also astringent, and contains so large an amount of tannin that in northern Europe it is deemed nearly as valuable as oak bark in preparing leather. The wood of the willows is light but firm, and where it is abundant is employed for many of the purposes for which pine is used; it serves for house timber, and small sailing vessels are built of it; it is very durable when kept constantly under water and when quite dry, but soon decays if exposed to the weather; common casks, farm implements, lasts, ladders, and turned wares are among the articles made from it. It makes a quick clear fire, and burns readily when green; its charcoal is much esteemed for gunpowder, and also serves to make sketching crayons. In some countries cattle are fed upon the leaves, which are collected And stored for winter forage.
The character of the twigs or slender branches of several species especially adapts them to basket making. (See Osier.) - The most important species is the white willow (salix alba), common throughout Europe and western Asia, and extensively naturalized in this country. It forms a handsome tree 50 to 80 ft. high; the young shoots are green; the narrowly lanceolate, pointed, serrate leaves, when young, are silky on both sides, smooth above when old, but always dull green; the flowers are borne at the ends of lateral leafy shoots, appearing in May and June, the stamens always two to each scale. This is a most valuable tree for prairie countries, either for itself, or as rapidly furnishing protection for other trees, and immense numbers are planted annually. When the trees are set thickly, they rapidly produce long straight poles for fences and furnish a supply of fuel. It is sometimes planted very closely to form a live fence or tall hedge, but there is much doubt as to its permanence when thus treated. In Maryland and Delaware it is planted to furnish charcoal to the powder mills.
The golden willow or yellow osier, formerly regarded as a distinct species, is a variety of the white (var. vitellina), with its young shoots bright yellow, rather shorter and broader leaves, and a more spreading habit; this, in the older states, is very generally introduced and much more common than the type; in Europe it is often cultivated as an osier. Another variety of the white is the blue willow (var. coerulea), which has its leaves less downy beneath and of a more bluish green; this is considered a much more rapid grower than the white, and in England it is asserted that it will produce a greater amount of timber than can be obtained in the same period from any other tree. - The brittle or crack willow (S. fragilis), so called because the young shoots readily break away from the branches, is much less common in this country than the preceding, though considerably planted in the older states; it grows larger and more rapidly than the white, from which it differs principally in having greener and smooth leaves, the teeth upon which are inflexed, and in its larger and looser catkins. In England this is regarded as the most valuable willow for timber, its wood being harder than that of any other, the heart wood of a deep reddish color.
The varnished willow (var. decipiens), the Bedford willow (var. Russelliana), and the green willow (var. viridis), formerly classed as species under the names here given for the varieties, are forms of this, and are sometimes cultivated as osiers.
Willow - Staminate and Pistillate Flowers.
1. Staminate Catkin. 2. Staminate Flower. 8. Pistillate Catkin. 4. Pistillate Flower.
Weeping Willow (Salix Babylonica).
Glossy Willow (Salix lucida).
The weeping willow (S. Babylonica), a native of Asia and northern Africa, is supposed to have been introduced into Europe by Tournefort from the Levant in 1702. Being so frequently planted, its long, slender, pendulous branches and linear-lanceolate leaves are very familiar; only the pistillate sex has been introduced into this country. It grows to a large size, is one of the first trees to leaf out in spring, and holds its foliage until the killing frosts. A curious variety (var. annularis) has its leaves coiled into a ring, and is called the ring-leaved or hoop willow. The American weeping willow of the nurseries is a partly pendulous form of the European purple willow (S. purpurea), and needs much training to keep it in shape. The Kilmarnock weeping willow is a remarkable variety of the European sallow willow (S. caprea), the branches of which are sharply reflexed; when grafted 7 or 8 ft. high on other species, it makes an interesting lawn tree. - The most beautiful of the genus is the native shining willow (S. lucida), which grows from Pennsylvania northward, and in British America from ocean to ocean; in cultivation it grows to 15 or 20 ft. high, but in the wild state it flowers when only 3 ft., forming a handsome head with dark green branches; the leaves, 3 to 5 in. long, have a long tapering point and are smooth and shining on both sides; the flowers appear on short leafy branches.
This is becoming deservedly popular as an ornamental tree, and is so much like the bay willow (S. pentandra) of Europe, that some botanists consider them the same. There are several prostrate alpine species, some of which are found on our higher mountains; among them is the interesting herb-like willow (3. herbacea), which, in marked contrast with the lofty white and weeping species, rarely reaches 2 in. in height, and bears disproportionately large catkins.
Herb-like Willow (Salix herbacea).