FAMILY SALICACEÆ

Genus SALIX

CHIEFLY quick-growing, water-loving trees and shrubs, with slender, supple twigs, and buds with a single protective cap or scale of two coats. Wood light, soft. Leaves simple, alternate, narrow and pointed, deciduous. Flowers diœcious, in loose catkins, each flower subtended by a bract having an entire hairy margin. Fruit a 2-valved pod with papery walls; seeds minute, in copious hairy floats.

A. Shape of leaves linear-lanceolate, taper pointed.

B. Leaves green on both sides.

C. Stipules persistent. (S. nigra) BLACK WILLOW

CC. Stipules deciduous. (S. fluviatilis) SANDBAR WILLOW

BB. Leaves pale and silky, hairy below. (S. sessilifolia) WILLOW

AA. Shape of leaves lanceolate, sharp pointed.

B. Stamens more than 2 on each scale of catkin.

C. Petioles without glands.

D. Leaves silvery beneath. (S. longipes) BLACK WİLLOW

DD. Leaves glaucous beneath.

E. Petioles slender; leaves thin, pale green. (S. amygdaloides) PEACH WILLOW

EE. Petioles stout; leaves leathery, dark green. (S. lavigata) BLACK WILLOW

CC. Petioles with glands at apex; leaves dark green, lustrous, pale beneath.

D. Leaves leathery. (S. lucida) SHINING WILLOW

DD. Leaves not leathery. (S. lasiandra) BLACK WILLOW

BB. Stamens 2 on each scale of catkin.

C. Leaves pubescent and silvery beneath. (S. Missouriensis) MISSOURI WILLOW

CC. Leaves smooth, with pale linings.

D. Leaf linings silvery; blades broad. (S. discolor) PUSSY WILLOW

DD. Leaf linings pale; blades narrow. (S. cordata, var. Mackenzieana) HEART WILLOW

AAA. Shape of leaves oblong or ovate.

B. Leaf linings pubescent, white.

C. Apex blunt (S. Hookeriana) WILLOW

CC. Apex short pointed (S. Bebbiana) WILLOW

BB. Leaf linings smooth, pale; apex blunt. (S. balsamifera) WILLOW

The genus Salix is distributed from the equator to the Arctic circle. It embraces 170 species, beside numbers of natural hybrids between closely related species. Most of them prefer moist soil; a few prefer dry. They ascend from sea level to the tops of mountain chains. They vary from great trees to prostrate shrubs. No climate or soil but can show its native willows. Among woody plants they are comparable to grass among the herbs.

The wood of willow is uniformly light and weak. The trees are likely to get less than their due of credit, when compared with the average large genus of hardwoods or conifers. But uses have been found for them from time immemorial. Their soft, light wood makes superior charcoal for gunpowder and other uses, and is largely used for summer fuel where a quick, hot fire is desirable. The tough, flexible twigs of several species form the basis of the wickerware industry. Tannin is obtained from the bitter bark. In Holland and other countries willows are planted to hold the banks of streams and ditches. Willow branches formed the original jetties that opened and kept open to navigation the channel of the Mississippi. Willows are among our best trees for quick-growing shelter belts, in the newer parts of the country. They furnish ornamental and shade trees of value—pretty when young, dignified in age.

The cultivation of willows is very easy. A twig stuck into moist soil grows into a tree. Willow posts set out green soon row into roadside trees, thus serving a double purpose. In damp situations their roots drain and greatly improve the land. Many species have twigs that snap off at the base. These twigs strike root if they fall on damp ground; many waterside willows cast their twigs in this way, and the stream carries them down, lodging them on shoals and bars, which soon become clothed with trees. It is an unmeasured advantage to a region to have its shifting sands and mud banks established thus, and covered with green.

There are comparatively few willows that grow into large trees. The rank and file of trees even in these species are small. From Europe we have naturalised two large species, S. alba and S. fragilis. The golden osier, whose yellow limbs are bright in early spring in many a fence row, is called var. vitellina of S. alba, the white willow of Europe. The Babylonian willow, Salix Babylonica, is the much-planted weeping willow of the Eastern States. Var. dolorosa is the popular “Wisconsin Weeping Willow.” One of the best ornamental willows is S. pentandra, the laurel willow, whose crown of glossy, broad, green leaves adorns many parks. This species is coming into well-deserved popular favour. The Kilmarnock Willow is a weeping horticultural variety, pendula, of S. Caprea, Linn., the European goat willow. The staminate tree is loaded in spring with catkins which are coarse and ugly compared with those of our own pussy willow, S. discolor.

Black Willow (Salix nigra, Marsh.)—Medium-sized tree, 50 to 100 feet high, but usually smaller. Twigs slender, brittle at base. Bark dark brown, flaky, deeply furrowed, often shaggy. Wood light reddish brown, weak, soft, fine grained. Buds small, acute, red-brown. Leaves narrowly lanceolate, acuminate at apex, finely and evenly serrate, green on both sides; petioles short, 2 ½ to 5 inches long; stipules leaf-like, semi heart shaped or crescent shaped, deciduous or persistent. Flowers with leaves, on short lateral twigs, diœcious; catkins 1 to 3 inches long, pencil-like, erect; ovaries short, distinct, smooth; stamens 3 to 7; scales oval, hairy, deciduous. Fruit loose racemed capsules, ovoid tapering; seeds minute. Preferred habitat, borders of lakes and streams. Distribution, Newfoundland to Florida, west to Rocky Mountains, reappearing in California.

The black willow earns its name by the black bark of old trees. An interesting feature of the foliage is the pair of leaf-like, heart-shaped stipules that persist throughout the summer, as a rule, at the base of each leaf. Among narrow-leaved willows this is the only one with foliage uniformly green on both sides. The leaves are often curved like a sickle. No willow has a wider distribution than this intrepid species, which takes possession of stream borders, climbs mountains and crosses arid plains to plant itself in new territory. It is one of the largest of our native species when it comes to maturity.

The Black Willow (S. longipes, Anders.) differs from S. nigra in the wider, more typically lanceolate leaf and the silvery lining which lightens the foliage mass wonderfully as the wind plays among the leaves. The two heart-shaped stipules are usually persistent; they can always be found near the tips of growing shoots, even in midsummer.

The centre of this tree’s distribution is in the Ozark Mountains. Rocky banks of streams are its preferred habitat. It grows, a small tree, from Washington, D. C., to Florida, and west to Missouri and New Mexico.

Sandbar Willow (Salix fluviatilis, Nutt.)—Slender tree, 20 to 30 feet high, or much-branched shrub. Leaves silky, becoming smooth, linear-lanceolate, coarsely toothed, tapering at both ends, often falcate, 2 to 4 inches long, thin yellow-green, paler beneath; petioles short; midrib raised, prominent; stipules minute, leafy, deciduous. Flowers in slender, silky aments on leafy side twigs. Fruits ovoid-conic, sessile, scales smooth. Preferred habitat, moist soil along streams. Distribution, Quebec to Northwest Territory; south to Virginia, Kentucky and New Mexico.

The sandbar willow, like S. nigra, does a good work in holding in place a body of drift which without them would be moved by floods. The beautifying of rivers by embowering the mud flats and sandy shoals in billowy green is a distinct claim this tree has to the gratitude of communities. A little tree, indeed, but widely distributed, it is one of the most useful. A variety, argyrophylla, with silky, downy leaf, is found from Texas west to California and north to British Columbia.

The Silver-leaved Willow (Salix sessilifolia, Nutt.), with scarcely any stem for its narrow silky-lined leaves, is a little tree that follows stream borders from Puget Sound south to the western slopes of the Sierra Nevada. It is one of the commonest willows of the coast region of southern California. The hoary tomentum that clothes the opening leaves is never quite lost from the under sides of the leaves. They are pale yellow-green on the upper sides at maturity.

Peach-leaf Willow (Salix amygdaloides, Anders.)—Erect, straight-branched tree, 30 to 40 feet high, rarely 70 feet high. Bark brown, scaly, on thick plates. Wood soft, weak, pale brown Buds ovate, lustrous, brown. Leaves broadly lanceolate or ovate, serrate, taper pointed, 3 to 5 inches long, 1 inch wide, glabrous, paler, and glaucous beneath; petioles slender, compressed; stipules kidney shaped, broad, serrate, soon dropping. Flowers with the leaves, catkins loosely flowered, I to 2 inches long. Fruits narrowly ovoid capsules, taper pointed, smooth on stem of equal length. Preferred habitat, borders of streams and lakes. Distribution, Quebec to British Columbia, south through New York, Missouri and New Mexico.

The resemblance of the foliage of this tree to that of peach trees is striking. The leaves curl slightly, and hang pendant on their slender, flexible stems. It is one of our few willow trees that rise above medium height. Rare in the East, it is common in the valley of the Ohio, and along streams that flow down the eastern slopes of the Rocky Mountains. It is often met in cultivation in the Middle West.

The Black Willow (S. lævigata, Bebb.) is recognisable by its pale blue-green, leathery leaves, which are pale and glaucous beneath and finely serrate or almost entire on the margins. It is a native of California, following streams on the western slopes of the Sierras. It is rarely more than 40 feet high, averaging a little over half that height.

The Shining Willow (S. lucida, Muehl.) is an inhabitant of the North. From Newfoundland it ranges westward to Hudson Bay and the Rockies, and southward only as far as Pennsylvania and Nebraska. A small, round-headed tree, its distinction is the lustre of its ruddy twigs and the beautiful sheen of its dark green, leathery leaves. It is coming to be recognised by landscape gardeners and nurserymen as a species of considerable horticultural value.

The Western Black Willow (S. lasiandra, Benth.) grows to be a tree 60 feet high on river banks and lake shores from British Columbia to California and east into Montana, Colorado, and New Mexico. The type becomes modified in the remote limits of its range. The leaves are 4 or 5 inches long, lanceolate and finely cut-toothed; they are a dark, lustrous green above, paler or glaucous below.

Missouri Willow (Salix Missouriensis, Bebb.)—Tree, to 50 feet high, with trunk to 1 ½ feet thick. Twigs pubescent. Bark grey, thin, with small scales. Wood dark brown. Leaves lanceolate, acuminate, finely serrate, with rounded bases, 3 to 6 inches long, to ½ to 1 ½ inches wide, pubescent at first, becoming smooth, green above, pale and glaucous below; stipules leaf-like in pairs, often persistent; petioles about ½ inch long. Flowers before leaves; aments slender, long; scales persistent, hairy; stamens 2; style short. Fruit capsules, stalked, narrowly ovoid, smooth, above hairy oval scale. Preferred habitat, river banks. Distribution, northern Missouri, northeastern Kansas, Nebraska and western Iowa.

Pussy Willow (Salix discolor, Muehl.)—Shrub, or small tree, to 25 feet high, with stout branchlets, purplish red with pubescent coating. Buds reddish, flattened, pointed. Leaves oblong-lanceolate, acute at both ends, irregularly serrate, often crenate, thick, 3 to 5 inches long, bright green, with pale or silvery lining; midribs broad, yellow; stipules leaf-like, half-moon shaped; petioles slender. Flowers, March, often showing earlier, before the leaves; aments silky, oval, grey, turning yellow as flowers open. Fruits aments of beaked capsules, each long pointed, on long stem, with broad, hairy scale. Preferred habitat, swamps and moist hillsides. Distribution, Nova Scotia to Manitoba; south to Delaware and Missouri.

This is the familiar bog willow which we rarely recognise in leaf. The twigs are usually cut when the little furry catkins peep out in late winter. Florists in Eastern cities buy large quantities of these twigs in winter, and force them out for the early spring trade.

The Heart Willow (S. cordata), a shrub in the East, has a Western variety, Mackenzieana, Hook., that assumes the tree habit and size. It extends from the far North to the Rocky Mountains in Idaho and west into California. The narrow leaves are acute at the apex and bear minute kidney-shaped stipules throughout the summer. It is an extremely variable willow.

The Hooker Willow (S. Hookeriana, Hook.) has broad, oblong leaves, blunt at apex, and white below, with hoary tomentum. It is the little willow of sand dunes and salt marshes from Vancouver Island to southern Oregon. Its hoary twigs further identify it. It rarely grows above 30 feet in height.

Bebb’s Willow (Salix Bebbiana, Sarg.)—Small tree, with short trunk, 10 to 20 feet high, with downy twigs and smooth reddish bark. Leaves 1 to 3 inches long, oblong-obovate, acute or blunt at apex, sparingly toothed or entire, dull green and downy above, distinctly veined and pale blue or silvery, hairy beneath; petioles short; stipules semi-cordate, acute, deciduous. Flowers with leaves, sessile, erect, terminal; staminate silky white, becoming golden; pistillate silky, with yellow stigmas which spread in pairs. Fruits pubescent, beaked capsules; stalk much longer than scale. Preferred habitat, dry soil or stream borders. Distribution, throughout British America and south to New Jersey, Nebraska and Utah.

The Balsam Willow (S. balsamifera, Barr.) is dressed in spring, like the Balm of Gilead, in young shoots that glisten in a coating of balsam. The broad, ovate leaves are blunt at the apex, and look scarcely willow-like, but the flowers and seed pods maintain the family traditions and leave us no doubts. The tree is found in the northern tier of states and ranges far north, becoming a prostrate shrub. In its best estate it grows into a long stem crowned with a small clump of branches bearing the foliage. It is an inhabitant of cold bogs, and extends no farther west than Minnesota.

Golden Osier (Salix alba, Linn., var. vitellina)—Venerable-looking tree, with short trunk and regular, spreading top, 40 to 60 feet high. Twigs golden yellow. Bark grey, rough. Leaves elliptical, sparingly serrate, tapering at both ends, 2 to 4 inches long, silky hairy, becoming smooth; lining white and somewhat hairy; stipules ovate-lanceolate, deciduous; petioles short. Flowers with leaves; scales deciduous; stamens 2; stigmas sessile. Fruits flask shaped, sessile, smooth capsules. Preferred habitat, moist, rich soil. Distribution, eastern North America.

This American derivative of the white willow of Europe deserves mention among native trees. It is truly naturalised. Its yellow twigs are its best identification. It is far more common in cultivation than its parent, although the latter is occasionally seen. This variety is one of the most vigorous and useful of all the willows grown in this country.