The White Alder (.4. 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.
The Lanceleaf Alder (A. oblongifolia, Torr.), whose name describes it well, comes up from the Peruvian Andes through Mexico, and is found at high altitudes along canon sides in New Mexico and Arizona.
The Paperleaf Alder (A. tenuifolia, Nutt.)—A small tree with thin, firm-textured leaves, ovate in shape with laciniate lobes, twice saw toothed, one of the prettiest of the alders, is abundant in thickets along the headwaters of streams that rise in the Western mountains. It follows the various ranges from British Columbia to Lower California, Colorado and northern New Mexico.
Poets do not always realise their responsibility. The one who characterised the trees that fringed the sluggish streams and cover the "water galls" in England as "the water spungie alder, good for naught," put into rhythmic form, too easy to remember, a stigma that brands a really picturesque and useful tree. The alder's primary virtue is that it will thrive in places so boggy that even willows and poplars cannot grow there. Can any lover of English landscapes spare the alders from unsightly places whose lines they soften and whose baldness they conceal with billows of living green? "He who would see the alder in perfection must follow the banks of the Mole, in Surrey, through the sweet vales of Dorking and Wickleham, into the groves of Esher." The English people cherish an affectionate regard for their native black alder, a description of which follows. The hawthorns of their hedgerows are not more a part of the life of the people. John Evelyn expresses the sentiment when, after recounting the many practical uses of the tree and its wood, he adds two more: "The fresh leaves alone applied to the naked sole of the foot, infinitely refresh the surbated traveller "; and "The very shadow of this tree doth feed and nourish the grass that grows under it." The Black Alder (Alnus glutinosa, Gxrtn.), native of Europe, Asia and North Africa, is the most picturesque of water-loving trees, with its dark green, round or oblong leaves glutinous when they unfold in the spring. The trees are tall and erect, with dark trunks. The tallest sometimes reach 70 feet and have a trunk diameter of 3 feet. These giant alders are dignified, indeed, but the rank and file of the species are smaller trees. They hang out their long yellow catkin fringe on the bare twigs in earliest spring, a sight to repay a visit, even if it involved the wearing of rubber boots; and the little green knobs on the branching side stems grow by autumn into ripe cones, out of whose slits fall the little flat seeds.
Compared with oak and ash timber, alder is indifferent in quality and does not interest the lumberman, but there are special uses to which alder is always put. Growing in water, it seems to recognise its element; alder piles, water pipes, pumps and watering troughs kept always saturated last indefinitely. The piles of the Rialto in Venice and those of Amsterdam, ac cording to ancient authorities, are of alder. Exposed to conditions of alternate wet and dry, the wood soon rots. It was a canny Scot who buried alder boards in a peat bog, in which lime was also thrown. This prevented the invasion of destructive insects, and turned the pinkish brown wood to the colour and hardness of mahogany. The grain of alder is smooth, fine and lustrous. It does not warp nor splinter. In the old days it was a wood for the boatbuilder. "Excepting Noah's Ark, the first vessels we read of were made of alder." Virgil gives a pretty glimpse o' northern Italy in one of his Georgics: "And down the rapid Po light alders glide." 18o Alder wood serves many cheap and common uses: for sabots and clogs, and wooden heels; truncheons, kneading troughs, barrel staves, bobbins, trays, hop poles, and the like. The bark and cones yield tannin used in tanning leather and in medi cine, and a yellow dye which is also used in the making of ink. The best charcoal for gunpowder is made from willow and alder. Warty excrescences on old trees and twisted roots furnish the inlayer with small but beautifully veined and very hard pieces. Articles made of this once brought high prices.
One of the best uses to which alder is put is planting in hedges along borders of streams where their roots, closely inter lacing, hold the banks against crumbling.
The black alder is most often met in horticultural forms in America. There is a variety with large, shining leaves and red veins and petioles. The daintiest varieties are those with finely cut leaves, of which iniperialis, with fingered leaves like the white oak, is a good example.
The Hoary or Speckled Alder (Alnus incana, Willd.), native of both hemispheres, is a handsome tree of medium size in Europe and Asia, but it rarely rises above a shrub in America. It is second only to the black alder, from which it is easily dis tinguished, for its branches are speckled with white spots. Its leaves are pointed and lined with a hoary bloom; and there is nothing glutinous about the opening leaves and shoots. The wood is very similar to that of the other species.
Two Japanese species of alder have come into American gardens, both vigorous, large-leaved trees, of good size and excellent habit. Alnus Japonica has a pyramidal head of shining dark green foliage; Abuts tinctoria is round headed, with handsome foliage, and is proving hardy and rapid of growth in New England. A cardinal merit of these cultivated alders is that they thrive in ordinary garden soil.