SALICACEAE
Aspen
Populus tremuloides Michx.
HABIT.—A small, slender tree generally 35-45 feet high, with a trunk diameter of 8-15 inches; forming a loose, rounded crown of slender branches.
LEAVES.—Alternate, simple, 1-1/2-2-1/2 inches long and broad; broadly ovate to suborbicular; finely serrate; thin and firm; lustrous, dark green above, dull and pale beneath; petioles slender, laterally compressed. Tremulous with the slightest breeze.
FLOWERS.—April, before the leaves; dioecious; the staminate catkins 1-1/2-3 inches long, the pistillate at first about the same length, gradually elongating; calyx 0; corolla 0; stamens 6-12; stigmas 2, 2-lobed, red.
FRUIT.—May-June; 2-valved, oblong-cylindrical, short-pedicelled capsules 1/4 inch long; seeds light brown, white-hairy.
WINTER-BUDS.—Terminal bud about 1/4 inch long, narrow-conical, acute, red-brown, lustrous; lateral buds often appressed.
BARK.—Twigs very lustrous, red-brown, becoming grayish and roughened by the elevated leaf-scars; thin, yellowish or greenish and smooth on the trunk, often roughened with darker, horizontal bands or wart-like excrescences, becoming thick and fissured, almost black at the base of old trunks.
WOOD.—Light, soft, weak, close-grained, not durable, light brown, with thin, whitish sapwood.