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Key to Species — Part 19

A. Flowers in autumn. (A. maritima) 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 narrowly 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. tenuifolia) 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 30 feet, with slender branches. Bark thin, smooth, light brown; twigs greyish. Wood soft, light brown, close grained. Buds acute, dark red, 1/4 inch long, with silky pubescence. Leaves 3 to 4 inches long, oblong, ovate or obovate, acute at both ends, shining dark green above, pale green and dull beneath, edges set with fine incurving teeth; petioles short. Flowers autumnal, from buds of previous spring; monoecious; staminate catkins, golden, 1 to 2 inches long; pistillate, oblong, 1/8 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 80 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.

The White Alder (A. rhombifolia, Nutt.), equal in size to the preceding species, grows along the mountain streams from northern Idaho to southern California. It has a white scurf on its new shoots and the opening leaves are clothed with white hairs. Its wide sap wood is also white. The tree's spring appearance probably justifies its name. The irregularly diamond-shaped leaves are sharply and finely cut on thin wavy margins.

The wonderful thing about this tree is its blooming in January or February, hanging its conspicuous yellow catkins out while yet all other trees are asleep. Even in California this is a striking phenomenon along the mountain streams fringed with these trees.

The bark of the trunks of white alder is furrowed and dark brown. The trees need not be confused with the Oregon alder, if the trunk be examined.