5. Staminate flower, enlarged.
6. Pistillate flower, enlarged.
7. Fruiting branchlet, × 1/2.
8. Fruit, × 3-1/2.
BETULACEAE
Paper Birch. Canoe Birch. White Birch
Betula alba papyrifera (Marsh.) Spach. [Betula papyrifera Marsh.]
HABIT.—A tree 50-75 feet high, with a trunk diameter of 1-3 feet, forming in youth a compact, pyramidal crown of many slender branches, becoming in old age a long, branchless trunk with a broad, open crown, composed of a few large limbs ascending at an acute angle, with almost horizontal branches and a slender, flexible spray.
LEAVES.—Alternate, simple, 2-3 inches long, 1-1/2-2 inches broad; ovate; coarsely, more or less doubly serrate; thick and firm; glabrous, dark green above, lighter beneath, covered with minute black glands; petioles stout, yellow, glandular, glabrous or pubescent.