THE ALDERS - FAMILY BETULACEAE. Genus ALNUS, Linn. Small water-loving trees of rapid growth. Leaves simple, deciduous, alternate, short stemmed. Flowers apetalous, monce in catkins. Fruit woody, cone-like, oval, with 2 seeds on each scale.
KeY TO SPECIES A. Flowers in autumn. (A. nzaritima) SEASIDE ALDER AA. Flowers before leaves in winter or early spring.
B. Staminate catkins becoming 4 to 6 inches long.
C. Bark smooth, pale grey or white; tree with nar rowly pyramidal head. (A. Oregona) RED ALDER CC. Bark ridged, dark brown; tree with wide, open head. (A. rhombifolia) WHITE ALDER BB. Staminate catkins becoming 2 to 3 inches long.
C. Leaves narrow, tapering to base and apex.
(A. oblongifolia) LANCELEAF ALDER CC. Leaves broad, oval, papery.
(A. tenttifolia) PAPERLEAF ALDER AaA. Flowers after the leaves in spring or summer.
(A. Sitchensis) ALASKA ALDER The genus Alnus includes twenty species of shrubs and trees, nine in North America, six of which are trees in habit and size. The largest and most important timber tree is the black alder of the Old World. Widely distributed by Nature and by man, this genus is the source of many hardy ornamentals adapted to damp soils.
"Alder, the owner of all waterish ground." Seaside Alder (Alnus maritima, Nutt.)—A round-topped tree 15 to 3o feet, with slender branches. Bark thin, smooth, brown; twigs greyish. Wood soft, light brown, close grained.
Buds acute, dark red, I inch long, with silky pubescence. Leaves 3 to 4 inches long, oblong, ovate or obovate, acute at both encs, shining dark green above, pale green and dull beneath, edges set with fine incurving teeth; petioles short. Flowers autumnal, from buds of previous spring; moncecious; staminate catkins, golden, t to 2 inches long; pistillate, oblong, * inch long, with red tips of stigmas protruding from scales. Fruit, a woody, oval strobile, ripe a year after blooming; scales thick, shiny, each bears two flat, obovate, pointed nuts or seeds. Preferred habitat, borders of streams and ponds, near, but not actually on, seacoast. Distribution, eastern Delaware and Maryland, Indian Territory.
Uses: Rarely planted, but deserving of cultivation for its glossy foliage and the beauty and unusualness of its golden catkins, appearing in September.
The seaside alder divides with the witch hazel the distinction of bearing flowers and ripening fruit simultaneously in the fall of the year. They do not compete for popular favour, because the alder comes first, hanging out its golden catkins in clusters on the ends of the season's shoots in August and September. Nothing is left of them when the witch hazel scatters its dainty stars along the twigs in October and November. The tiny pistillate cones of the alder are scarcely larger than the buds that keep them company.
The seaside alder grows well in the Arnold Arboretum, at Boston, flowering profusely, thus proving itself hardy in New England, and comfortable in dryer soil than it naturally chooses. It is quite worthy of the attention of those who seek for beauty and novelty of habit among little native trees.
The Oregon, or Red Alder (A. Oregona, Nutt.), is a large tree for an alder, sometimes 8o feet in height, with a narrow pyramid of drooping branches about a trunk that may exceed 3 feet in diameter. The smooth, pale grey bark of this tree sets it apart from other alders. The flowers and strobiles are large to match the tree; the ovate leaves are crenately lobed and finely cut toothed. They are lined with rusty pubescence, and are usually smooth and dark green above.
This is the alder of the Western coast that climbs mountains until it leaves the spruces behind, but reaches its greatest size about Puget Sound. From Sitka south through Washington and Oregon it lines the stream borders, and along the mountains it reaches as far as Santa Barbara in California. It loves also the canon sides in the coast range.
The reddish-brown wood is beautifully satiny when polished. It is light and easily worked, and though weak and brittle is made into furniture. The Indians make "dug-outs" of the butts of large trees.