Black Willow (Salix nigra, Marsh.)—Medium-sized tree, 5o to too 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, 21 to 5 inches long; stipules leaf-like, semi heart shaped or crescent shaped, deciduous or persistent. Flowers with leaves, on short lateral twigs, dicecious; 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, zo to 3o 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.
Willow (Salix amygdaloides, Anders.)—Erect, straight-branched tree, 3o to 4o 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, t 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 cultiva tion in the Middle West.
The Black Willow (S. lcevigata, 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. 1 t is a native of California, following streams on the western slopes of the Sierras. It is rarely more than 4o feet high, averaging a little over half that height.