In winter, a more intimate acquaintance can be made with deciduous trees. For it is only after the leaves have fallen that the architecture of trees can be clearly discerned. Every species has a different form. No individual, ever is exactly like another. A tree with its delicate tracery of leafless branches is a thing of beauty to eyes that are adjusted to see it. Note, then, the different kinds of bark, the direction of the cleavage; whether it is deep or shallow, smooth or shaggy; laid in smocking, as in white ash, or broken into coral-form bosses, as in Hackberry; or in plates with curled edges, as in black cherry. Sober colors merge and blend in trunk and branches to break in the outmost twigs into livelier tints of olive, ash-pink, red, or yellow, according to the species.
To one versed in tree-craft, a single twig is sufficient to identify the species. Is the twig stout or slender, rigid or flexible? How are the buds arranged, and what is their shape size, surface, and color? The leaf and flower buds, if separate, can be distinguished by their size and shape, the flower buds usually the larger. Particularly decorative is the alder, displaying three sorts of buds - purple oblong leaf buds, tiny buds of pistillate flowers, and staminate in three-finger aments -- together with brown cones, the receptacles of last year’s fruit. The buds of basswood are coated with red shellac, of box elder with mouse-colored fur, while those of sycamore are hidden within the hollow leafstalk. Buds of swamp hickory are sulphur yellow, buds of white elm resemble apple seeds; those of red elm are covered with rust colored wool. The leaf scars below the buds vary, also the arrangement on them of the little dots --the ends of wood bundles that divide to form the venation of the leaf. The rings of bud-scale scars, marking off the annual growths of the branch, also instance the saying that “Nature repeats herself with a difference.” In the maples, for example, these rings are wider and shallower than in the poplars, where they are deeply indented.
A small pinetum has been established on the hillside northwest of the tamarack swamp [map below]. As the deciduous tamarack is the only conifer growing naturally in the Garden all the evergreen trees therein are juveniles. They have been placed in accordance with their predilections for dryness or moisture --red cedar, jack, white and red pines, prostrate junipers highest on the slope, followed to the level below by white spruce (Taxus canadensis) and hemlock along the brook. Hemlock has not been listed among Minnesotan plants; but it has sneaked in, contrary to rule, with the idea that it may sometime break across the Wisconsin border. In order that the face of nature may be changed as little as possible in our trained wilderness, only a few specimens each of the state flora not indigenous to the Garden are admitted.