Box Elder. Ash-leaved Maple.
Habitat and Range.—In deep, moist soil; river valleys and borders of swamps.
Infrequent from eastern Ontario to Lake of the Woods; abundant from Manitoba westward to the Rocky mountains south of 55° north latitude.
Maine,—along the St. John and its tributaries, especially in the French villages, the commonest roadside tree, brought in from the wild state according to the people there; thoroughly established young trees, originating from planted specimens, in various parts of the state; New Hampshire,—occasional along the Connecticut, abundant at Walpole; extending northward as far as South Charlestown (W. F. Flint in lit.); Vermont,—shores of the Winooski river and of Lake Champlain; Connecticut,—banks of the Housatonic river at New Milford, Cornwall Bridge, and Lime Rock station.
South to Florida; west to the Rocky and Wahsatch mountains, reaching its greatest size in the river bottoms of the Ohio and its tributaries.
Habit.—A small but handsome tree, 30-40 feet high, with a diameter of 1-2 feet. Trunk separating at a small height, occasionally a foot or two from the ground, into several wide-spreading branches, forming a broad, roundish, open head, characterized by lively green branchlets and foliage, delicate flowers and abundant, long, loose racemes of yellowish-green keys hanging till late autumn, the stems clinging throughout the winter.
Bark.—Bark of trunk when young, smooth, yellowish-green, in old trees becoming grayish-brown and ridgy; smaller branchlets greenish-yellow; season's shoots pale green or sometimes reddish-purple, smooth and shining or sometimes glaucous.
Winter Buds and Leaves.—Buds small, ovate, enclosed in two dull-red, minutely pubescent scales. Leaves pinnately compound, opposite; leaflets usually 3, sometimes 5 or 7, 2-4 inches long, 1½-2½ inches broad, light green above, paler beneath and woolly when opening, slightly pubescent at maturity, ovate or oval, irregularly and remotely coarse-toothed mostly above the middle, 3-lobed or nearly entire; apex acute; base extremely variable; veins prominent; petioles 2-3 inches long, enlarging at the base, leaving, when they fall, conspicuous leaf-scars which unite at an angle midway between the winter buds.
Inflorescence.—April 1-15. Flowers appearing at the ends of the preceding year's shoots as the leaf-buds begin to open, small, greenish-yellow; sterile and fertile on separate trees,—the sterile in clusters, on long, hairy, drooping, thread-like stems; the calyx hairy, 5-lobed, with about 5 hairy-stemmed, much-projecting linear anthers; pistil none: the fertile in delicate, pendent racemes, scarcely distinguishable at a distance from the foliage; ovary pubescent, rising out of the calyx; styles long, divergent; stamens none.
Fruit.—Loose, pendent, greenish-yellow racemes, 6-8 inches long, the slender-pediceled keys joined at a wide angle, broadest and often somewhat wavy near the extremity, dropping in late autumn from the reddish stems, which hang on till spring.