THE BLACK ALDER.
Alnus glutinosa, Gaertn.
Of the alders, the black alders of Europe is the largest and most important timber tree. Its range includes west ern Asia and northern Africa. It was introduced success fully into our Northeastern states in colonial times and has become naturalized in many localities. These trees some times reach seventy feet in height and a trunk diameter of three feet. Their dark green foliage, glutinous when the leaves unfold in the spring, ranks these giant alders among the beautiful and picturesque trees.
The lumberman esteems alder wood only for special purposes. It grows in water and its wood resists decay bet ter than any other kind when saturated through indefinite periods. In the old clays it was the wood for the boat builder. The piles of the Rialto in Venice and along the canals of Amsterdam and other Dutch cities are of black alder. Water pipes and troughs, pumps, barrel staves, kneading troughs, sabots and clogs were made of alder wood. The bark and cones are rich in tannin and a yellow dye used in making ink. Willow and alder make the best
charcoal for gunpowder. Warty excrescences on old trees and twisted roots furnished the inlayer with small but beautifully veined and very hard pieces, beautiful in veneer work when polished. In America the black alder is often met in horticultural varieties. The daintiest are the cut-leaved forms, of which imperialis, with leaves fingered like a white oak, is a good example.
One of the best uses to which alders are put in Europe is planting in hedges along borders of streams, where their closely interlacing roots hold the banks from crumbling and keep the current clear in midstream. No English landscape is more beautiful than one through which a little river winds, its banks and the boggy spots tributary to it softened by billows of living green. "He who would see the alder in perfection must follow the banks of the Mole and Surrey through the sweet vales of Dorking and Wickle ham ."