Michigan Trees Part 22

+BETULACEAE+

+Yellow Birch. Gray Birch+

_Betula lutea Michx. f._

HABIT.--A tree 60-80 feet high and 2-4 feet in trunk diameter; numerous slender, pendulous branches form a broad, open, rounded crown.

LEAVES.--Alternate, solitary or in pairs, simple, 3-5 inches long and one-half as broad; ovate to oblong-ovate; sharply doubly serrate; dull dark green above, yellow-green beneath; petioles short, slender, grooved, hairy; slightly aromatic.

FLOWERS.--April, before the leaves; monoecious; the staminate catkins 3-4 inches long, slender, pendent, purplish yellow; the pistillate catkins sessile or nearly so, erect, almost 1 inch long, greenish.

FRUIT.--Ripens in autumn; sessile or short-stalked, erect, glabrous strobiles, about 1 inch long and half as thick; scales downy on the back and edges; nut about as broad as the wing.

WINTER-BUDS.--Terminal bud absent; lateral buds about 1/4 inch long, conical, acute, chestnut-brown, more or less appressed; bud-scales more or less p.u.b.escent.

BARK.--Twigs, branches and young stems smooth, very l.u.s.trous, silvery gray or light orange; becoming silvery yellow-gray as the trunk expands and breaking into strips more or less curled at the edges; old trunks becoming gray or blackish, dull, deeply and irregularly fissured into large, thin plates; somewhat aromatic, slightly bitter.

WOOD.--Heavy, very strong and hard, close-grained, light brown tinged with red, with thin, whitish sapwood.

DISTRIBUTION.--Throughout the state, but more abundant and of larger size northward.

HABITAT.--Prefers rich, moist uplands, but grows in wet or dry situations.

NOTES.--One of the largest deciduous-leaved trees of Michigan. Easily transplanted, but not desirable as a street tree.

[Ill.u.s.tration: +Paper Birch. Canoe Birch. White Birch+

1. Winter twig, 1.

2. Portion of twig, enlarged.

3. Leaf, 1.

4. Flowering branchlet, 1/2.

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._) _s.p.a.ch_. [_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; coa.r.s.ely, 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 p.u.b.escent.

FLOWERS.--April, before the leaves; monoecious; the staminate catkins cl.u.s.tered or in pairs, 3-4 inches long, slender, pendent, brownish; the pistillate catkins about 1-1/2 inches long, slender, erect or spreading, greenish; styles bright red.

FRUIT.--Ripens in autumn; long-stalked, cylindrical, glabrous, drooping strobiles, about 1-1/2 inches long; scales hairy on the margin; nut narrower than its wing.

WINTER-BUDS.--Terminal bud absent; lateral buds 1/4 inch long, narrow-ovoid, acute, flattish, slightly resinous, usually divergent.

BARK.--Twigs dull red, becoming l.u.s.trous orange-brown; bark of trunk and large limbs cream-white and l.u.s.trous on the outer surface, bright orange on the inner, separating freely into thin, papery layers, becoming furrowed and almost black near the ground.

WOOD.--Light, hard, strong, tough, very close-grained, light brown tinged with red, with thick, whitish sapwood.

DISTRIBUTION.--Lansing and northward. Common in central Michigan as a small tree. Of larger size in the Upper Peninsula.

HABITAT.--Prefers rich, moist hillsides; borders of streams, lakes and swamps; but is also found in drier situations.

NOTES.--A rapid grower in youth. The bark is used by the Indians and woodsmen for canoes, wigwams, baskets, torches, etc.

[Ill.u.s.tration: +Beech. White Beech+

1. Winter twig, 1.

2. Portion of twig, enlarged.

3. Leaf, 1.

4. Flowering branchlet, 3/4.

5. Staminate flower, enlarged.

6. Pistillate flower, enlarged.

7. Bur, opened, 1.

8. Nut, 1.]

+f.a.gACEAE+

+Beech. White Beech+

_f.a.gus grandifolia Ehrh._ [_f.a.gus atropunicea_ (_Marsh._) _Sudw._]

[_f.a.gus ferruginea Ait._] [_f.a.gus americana Sweet_]

HABIT.--A beautiful tree, rising commonly to a height of 50-75 feet, with a trunk diameter of 2-4 feet; in the forest, tall and slender, with short branches forming a narrow crown, in the open with a short, thick trunk and numerous slender, spreading branches, forming a broad, compact, rounded crown.

LEAVES.--Alternate, simple, 3-5 inches long, one-half as broad; oblong-ovate, ac.u.minate; coa.r.s.ely serrate, a vein terminating in each tooth; thin; dark blue-green above, light yellow-green and very l.u.s.trous beneath; petioles short, hairy.

FLOWERS.--April-May, with the leaves; monoecious; the staminate in globose heads 1 inch in diameter, on long, slender, hairy peduncles, yellow-green; calyx campanulate, 4-7-lobed, hairy; corolla 0; stamens 8-10; the pistillate on short, hairy peduncles in 2-flowered cl.u.s.ters surrounded by numerous awl-shaped, hairy bracts; calyx urn-shaped, 4-5-lobed; corolla 0; ovary 3-celled; styles 3.

FRUIT.--Ripens in autumn; a p.r.i.c.kly bur borne on stout, hairy peduncles, persistent on the branch after the nuts have fallen; nuts usually 3, 3/4 inch long, sharply tetrahedral, brownish; sweet and edible.

WINTER-BUDS.--Nearly 1 inch long, very slender, cylindrical, gradually taper-pointed, brownish, p.u.b.erulous.

BARK.--Twigs l.u.s.trous, olive-green, finally changing through brown to ashy gray; close, smooth, steel-gray on the trunk, often mottled by darker blotches and bands.