Michigan Trees Part 30

NOTES.--A good street tree, but less graceful in habit than _U.

americana_.

[Ill.u.s.tration: +Hackberry. Nettle-tree+

1. Winter twig, 1.

2. Portion of twig, enlarged.

3. Leaf, 3/4.

4. Flowering branchlet, 1/2.

5. Staminate flower, enlarged.

6. Pistillate flower, enlarged.

7. Fruit, 1.]

+URTICACEAE+

+Hackberry. Nettle-tree+

_Celtis occidentalis L._

HABIT.--A medium-sized tree, 40-60 feet high, with a short, straight trunk 1-2 feet in diameter which branches a few feet from the ground into a few large limbs and many slender, horizontal, zigzag branches, forming a broad, rounded crown.

LEAVES.--Alternate, simple, 2-4 inches long and one-half as broad; ovate to ovate-lanceolate, oblique at the base, usually long-pointed; coa.r.s.ely serrate above the entire base; thin; glabrous, light green above, paler beneath, turning light yellow late in autumn; petioles short, slender, hairy.

FLOWERS.--May, with or soon after the leaves; polygamo-monoecious; greenish; inconspicuous; on slender pedicels; the staminate in cl.u.s.ters at the base of the shoot, the pistillate usually solitary in the axils of the upper leaves; calyx greenish, deeply 5-lobed; corolla 0; stamens 5; ovary 1-celled.

FRUIT.--September-October, remaining on the tree through the winter; slender-stalked, fleshy, globular drupes, 1/4 inch long, dark purple; edible.

WINTER-BUDS.--Terminal bud absent; lateral buds light brown, 1/4 inch long, ovoid, acute, flattened, the tip appressed.

BARK.--Twigs greenish, p.u.b.erulous, becoming l.u.s.trous, red-brown in their first winter; on old trunks thick, light brown or silvery gray, broken into deep, short ridges or warty excrescences.

WOOD.--Heavy, soft, coa.r.s.e-grained, weak, light yellow, with thick, whitish sapwood.

DISTRIBUTION.--Common throughout the Lower Peninsula.

HABITAT.--Prefers rich, moist, well-drained soil, but will grow on gravelly or rocky hillsides. Common along river-banks.

NOTES.--Hardy throughout its range. Grows slowly and irregularly in youth. Easily transplanted. Not desirable as a street tree, but appears well in ornamental grounds. Very tolerant of shade.

[Ill.u.s.tration: +Osage Orange+

1. Winter twig, 1.

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, 1/4.]

+URTICACEAE+

+Osage Orange+

_Maclura pomifera (Raf.) Schneider_ [_Toxylon pomiferum Raf._] [_Maclura aurantiaca Nutt._]

HABIT.--A tree 20-30 feet high, with a short trunk 1-2 feet in diameter; divides into a few large limbs with curving branches, forming a symmetrical, rounded crown.

LEAVES.--Alternate, simple, 3-5 inches long, 2-3 inches broad; ovate to oblong-lanceolate; entire; thick and firm; dark green and s.h.i.+ning above, paler beneath; petioles slender, p.u.b.escent, 1-1/2-2 inches long.

FLOWERS.--June, after the leaves; dioecious; the staminate slender-pedicelled, borne in a dense raceme at the end of long, slender, drooping peduncles; the pistillate in dense, globose heads at the end of short, stout peduncles; calyx 4-lobed, hairy; corolla 0; stamens 4; style covered with white, stigmatic hairs.

FRUIT.--Autumn; pale green, orange-like, 4-5 inches in diameter, composed of numerous small drupes, crowded and grown together.

WINTER-BUDS.--Terminal bud absent; lateral buds depressed-globular, partly hidden in the bark, pale brown.

BARK.--Twigs at first bright green, p.u.b.escent, becoming orange-brown and armed with stout, straight, axillary spines; dark orange-brown on the trunk and deeply furrowed.

WOOD.--Heavy, very hard and strong, flexible, coa.r.s.e-grained, very durable, bright orange, with thin, lemon colored sapwood.

NOTES.--A native of the South, but hardy throughout Michigan. A desirable ornamental tree. Extensively planted for hedges.

[Ill.u.s.tration: +Red Mulberry+

1. Winter twig, 1.

2. Portion of twig, enlarged.

3. Leaf, 1.

4. Spike of staminate flowers, 1.

5. Staminate flower, enlarged.

6. Spike of pistillate flowers, 1.

7. Pistillate flower, enlarged.

8. Fruit, 1.]

+URTICACEAE+

+Red Mulberry+

_Morus rubra L._

HABIT.--A small tree 20-30 feet high, with a short trunk 10-15 inches in diameter; forming a dense, round-topped crown of stout, spreading branches and more or less zigzag, slender branchlets.