Michigan Trees Part 16

4. Staminate flower, enlarged.

5. Pistillate catkin, 1/2.

6. Pistillate flower, enlarged.

7. Fruit, 1/2.]

+SALICACEAE+

+Cottonwood+

_Populus deltoides Marsh._ [_Populus monilifera Ait._]

HABIT.--A stately tree attaining a height of 70-90 feet and a trunk diameter of 3-5 feet; forming a spreading, open, symmetrical crown of ma.s.sive, horizontal branches and stout, more or less angled branchlets.

LEAVES.--Alternate, simple, 3-6 inches long, nearly as broad; broadly deltoid-ovate; coa.r.s.ely crenate-serrate above the entire base; thick and firm; l.u.s.trous, dark green above, paler beneath; petioles 2-3 inches long, slender, compressed laterally.

FLOWERS.--April-May, before the leaves; dioecious; the staminate in short-stalked, densely-flowered catkins 3-4 inches long; the pistillate in short-stalked, few-flowered catkins elongating to 6-8 inches; calyx 0; corolla 0; stamens very numerous, with red anthers; stigmas 3-4, spreading.

FRUIT.--May; 2-4-valved, short-stalked capsules, borne in drooping catkins 5-10 inches long; seeds light brown, densely cottony.

WINTER-BUDS.--Terminal bud 1/2 inch long, conical, acute, very resinous, s.h.i.+ning, brownish.

BARK.--Twigs and young stems smooth, yellow-green; old trunks ashy gray, deeply divided into straight furrows with broad, rounded ridges.

WOOD.--Light, soft, weak, close-grained, dark brown, with thick, whitish sapwood; warps badly and is difficult to season.

DISTRIBUTION.--Entire Michigan; rare in the northern portions.

HABITAT.--Prefers rich, moist soil; river-banks; river-bottoms; lake-sh.o.r.es; grows well in drier situations.

NOTES.--Rapid of growth, consequently an excellent tree for immediate effect. Propagated from cuttings.

[Ill.u.s.tration: +Lombardy Poplar+

1. Winter twig, 1.

2. Portion of twig, enlarged.

3. Leaf, 3/4.

4. Staminate flowering branchlet, 1/2.

5. Staminate flower, enlarged.]

+SALICACEAE+

+Lombardy Poplar+

_Populus nigra italica DuRoi_ [_Populus fastigiata Desf._] [_Populus dilatata Ait._]

HABIT.--A tree 75-100 feet high, with a short, ridged and b.u.t.tressed trunk 4-6 feet in diameter and a narrow, spire-like crown of erect branches.

LEAVES.--Alternate, simple, 2-4 inches long, and usually somewhat broader than long; broad-deltoid, abruptly ac.u.minate; finely but bluntly crenate-serrate; thick and firm; dark green and s.h.i.+ning above, lighter and more or less l.u.s.trous beneath; petioles slender, laterally compressed, 1-2 inches long.

FLOWERS.--April-May, before the leaves; dioecious; the staminate in sessile, dark red, cylindrical catkins about 3 inches long; the pistillate not present in the United States; calyx 0; corolla 0; stamens about 8, with white filaments and purple anthers.

FRUIT.--Not formed in the United States in the absence of pistillate flowers.

WINTER-BUDS.--Terminal bud conical, slightly angled, taper-pointed, glutinous, about 3/8 inch long; lateral buds smaller, appressed.

BARK.--Twigs glabrous, s.h.i.+ning yellow, becoming gray; thick and gray-brown on old trunks, deeply and irregularly furrowed.

WOOD.--Light, soft, easily worked, not liable to splinter, weak, not durable, light red-brown, with thick, nearly white sapwood.

NOTES.--Thought to be a native of Afghanistan. Very rapid in growth.

Short-lived. Spreads by means of suckers and fallen branches. Useful for ornamental purposes. Because of crowding the limbs die early, which remain and cause the tree to look unsightly.

+SUMMER KEY TO THE SPECIES OF JUGLANS+

a. Leaflets 11-17, the terminal usually present; pith of twigs chocolate-brown; bark of trunk rather smooth, or fissured, with broad, flat, whitish ridges; fruit elongated, sticky-downy. _J. cinerea_, p. 63.

aa. Leaflets 13-23, the terminal often lacking; pith of twigs cream colored; bark of trunk rough, brownish or blackish, deeply furrowed by broad, rounded ridges; fruit globose, not sticky-downy. _J. nigra_, p. 65.

+WINTER KEY TO THE SPECIES OF JUGLANS+

a. Pith chocolate-brown; leaf-scar with downy pad above; fruit elongated, sticky-downy; terminal bud 1/2-3/4 inch long; bark rather smooth, or fissured, with broad, flat, whitish ridges.

_J. cinerea_, p. 63.

aa. Pith cream colored; leaf-scar without downy pad above; fruit globose, not sticky-downy; terminal bud 1/3 inch long; bark rough, brownish or blackish, deeply furrowed by broad, rounded ridges. _J. nigra_, p. 65.

[Ill.u.s.tration: +b.u.t.ternut+

1. Winter twig, 1.

2. Leaf, 1/6 3. Leaflet, 1/2 4. Flowering branchlet, 1/2.

5. Staminate flower, enlarged.

6. Pistillate flower, enlarged.

7. Fruit, 1/2.]

+JUGLANDACEAE+

+b.u.t.ternut+

_Juglans cinerea L._

HABIT.--A medium-sized tree 40-60 feet high, with a short trunk 2-3 feet in diameter; forming a wide-spreading crown of large, horizontal branches and stout, stiff branchlets.