+ACERACEAE+

+Mountain Maple+

_Acer spicatum Lam._

HABIT.--A bushy tree sometimes 25-30 feet high, with a short trunk 6-8 inches in diameter; small, upright branches form a small, rounded crown.

More often a straggling shrub.

LEAVES.--Opposite, simple, 4-5 inches long and two-thirds as broad; 3-lobed above the middle, the lobes coa.r.s.ely crenate-serrate with pointed teeth, the sinuses usually wide-angled and acute at the base; thin; glabrous, dark green above, covered with a whitish down beneath, turning scarlet and orange in autumn; veining prominent; petioles long, slender, with enlarged base.

FLOWERS.--June, after the leaves are full grown; polygamo-monoecious; small, yellow-green; in erect, slightly compound, many-flowered, long-stemmed, terminal racemes; calyx downy, 5-lobed; petals 5; stamens 7-8; ovary tomentose.

FRUIT.--July; bright red, turning brown in late autumn; small, glabrous, paired samaras, in pendulous, racemose cl.u.s.ters.

WINTER-BUDS.--Small, flattish, acute, bright red, more or less tomentose; the terminal 1/8 inch long, containing the flowers.

BARK.--Twigs reddish, slightly hairy; very thin, red-brown, smooth or slightly furrowed on the trunk.

WOOD.--Light, soft, close-grained, light brown, with thick, lighter colored sapwood.

DISTRIBUTION.--Common in the Upper Peninsula; extends as far south as Saginaw Bay.

HABITAT.--Damp forests; rocky woods; along streams; always in the shade of other trees.

NOTES.--Forms much of the undergrowth of our northern forests. Little used, except for fire-wood.

[Ill.u.s.tration: +Sugar Maple. Hard Maple. Rock Maple+

1. Winter twig, 2.

2. Portion of twig, enlarged.

3. Leaf, 1/2.

4. Staminate flowering branchlet, 1/2.

5. Staminate flower, enlarged.

6. Pistillate flowering branchlet, 1/2.

7. Pistillate flower, enlarged.

8. Fruit, 1.]

+ACERACEAE+

+Sugar Maple. Hard Maple. Rock Maple+

_Acer saccharum Marsh._ [_Acer saccharinum w.a.n.g._]

HABIT.--A stately tree 60-100 feet in height, with a trunk diameter of 3-4 feet; in the open forming stout, upright branches near the ground, in forests making remarkably clean trunks to a good height; the crown is a broad, round-topped dome.

LEAVES.--Opposite, simple, 3-5 inches long and broad; usually 5-lobed (sometimes 3-lobed), the lobes sparingly wavy-toothed, the sinuses broad and rounded at the base; thin and firm; opaque, dark green above, lighter and glabrous beneath, turning yellow and red in autumn; petioles long, slender.

FLOWERS.--May, with the leaves; polygamo-monoecious or dioecious; on thread-like, hairy pedicels in nearly sessile corymbs; greenish yellow; calyx campanulate, 5-lobed; corolla 0; stamens 7-8; ovary hairy.

FRUIT.--September-October, germinating the following spring; paired samaras, glabrous, with wings about 1 inch long, diverging slightly.

WINTER-BUDS.--Small, acute, red-brown, glabrous or somewhat p.u.b.escent toward the apex, the terminal 1/4 inch long, the lateral smaller, appressed.

BARK.--Twigs smooth, pale brown, becoming gray and smooth on the branches; old trunks dark gray, deeply furrowed, often cleaving up at one edge in long, thick plates.

WOOD.--Heavy, hard, strong, close-grained, tough, durable, light brown, with thin, lighter colored sapwood.

DISTRIBUTION.--Found throughout the entire state.

HABITAT.--Prefers moist, rich soil in valleys and uplands and moist, rocky slopes.

NOTES.--The most important hardwood in Michigan. The tree which produces the bulk of the maple sugar of the market.

[Ill.u.s.tration: +Black Maple. Black Sugar Maple+

1. Winter twig, 2.

2. Leaf, 1/2.

3. Flowering branchlet, 1/2.

4. Staminate flower, enlarged.

5. Pistillate flower, enlarged.

6. Fruit, 1.]

+ACERACEAE+

+Black Maple. Black Sugar Maple+

_Acer saccharum nigrum (Michx. f.) Britt._ [_Acer nigrum Michx._]

HABIT.--A stately tree, sometimes reaching a height of 80 feet, with a trunk diameter of 2-3 feet; branches stout, forming a broad, rounded, symmetrical crown.

LEAVES.--Opposite, simple, concave, 5-7 inches across, the breadth usually exceeding the length; usually 5-lobed at maturity, the two lower lobes being small, often reduced to a mere curve in the outline, the pointed lobes undulate or entire and narrowed from the broad, shallow sinuses; thick and firm; glabrous above, downy beneath; petioles stout, usually pendent, tomentose. The sides of the larger leaves often droop giving to the tree an air of depression.

FLOWERS.--May, with the leaves; monoecious; in nearly sessile, umbel-like corymbs; about 1/4 inch long, yellow, on slender, hairy pedicels 2-3 inches long; calyx campanulate, pilose, 5-lobed; corolla 0; stamens 7-8; ovary hairy.

FRUIT.--Ripens in autumn; glabrous, paired samaras, cl.u.s.tered on drooping pedicels; wings set wide apart, but only slightly diverging.

WINTER-BUDS.--Small, ovoid, acute, with dark red-brown, acute scales, h.o.a.ry-p.u.b.escent on the outer surface.

BARK.--Twigs smooth, pale gray; becoming thick, deeply furrowed and sometimes almost black on the trunk.

WOOD.--Hard, heavy, strong, close-grained, creamy white, with thin, lighter colored sapwood.

DISTRIBUTION.--Lower Peninsula, south-eastern portion.