cc. Terminal buds nearly 1 inch long; buds fragrant; twigs

usually red-brown and seldom strongly angled. _P. balsamifera_[E] p. 53. _P. candicans_[E] p. 55.

+SALICACEAE+

+White Poplar+

_Populus alba L._

HABIT.--A large tree 60-80 feet high, with a trunk diameter of 2-4 feet, forming a large, spreading, rounded or irregular crown of large, crooked branches and sparse, stout branchlets.

LEAVES.--Alternate, simple, 2-4 inches long and almost as broad; broadly ovate to suborbicular; irregularly toothed, sinuate, or sometimes 3-5-lobed; glabrous, dark green above, white-tomentose to glabrous beneath; petioles long, slender, flattened, tomentose.

FLOWERS.--April-May, before the leaves; dioecious; the staminate catkins thick, cylindrical, 2-4 inches long; the pistillate catkins slender, 1-2 inches long; calyx 0; corolla 0; stamens 6-16, with purple anthers; stigmas 2, branched, yellow.

FRUIT.--May-June; ovoid, 2-valved capsules, 1/8-1/4 inch long, borne in drooping catkins 2-4 inches long; seeds light brown, surrounded by long, white hairs.

WINTER-BUDS.--Ovoid, pointed, not viscid, downy, about 1/4 inch long.

BARK.--Twigs greenish, covered with a white down, becoming greenish gray and marked with darker blotches; dark gray and fissured at the base of old trunks.

WOOD.--Light, soft, weak, difficult to split, reddish yellow, with thick, whitish sapwood.

NOTES.--A native of Europe and Asia. Hardy in Michigan. Grows rapidly in good soils; thrives in poor soils and exposed situations. Roots deep, producing numerous suckers for a considerable distance from the tree.

+SALICACEAE+

+Aspen+

_Populus tremuloides Michx._

HABIT.--A small, slender tree generally 35-45 feet high, with a trunk diameter of 8-15 inches; forming a loose, rounded crown of slender branches.

LEAVES.--Alternate, simple, 1-1/2-2-1/2 inches long and broad; broadly ovate to suborbicular; finely serrate; thin and firm; lustrous, dark green above, dull and pale beneath; petioles slender, laterally compressed. Tremulous with the slightest breeze.

FLOWERS.--April, before the leaves; dioecious; the staminate catkins 1-1/2-3 inches long, the pistillate at first about the same length, gradually elongating; calyx 0; corolla 0; stamens 6-12; stigmas 2, 2-lobed, red.

FRUIT.--May-June; 2-valved, oblong-cylindrical, short-pedicelled capsules 1/4 inch long; seeds light brown, white-hairy.

WINTER-BUDS.--Terminal bud about 1/4 inch long, narrow-conical, acute, red-brown, lustrous; lateral buds often appressed.

BARK.--Twigs very lustrous, red-brown, becoming grayish and roughened by the elevated leaf-scars; thin, yellowish or greenish and smooth on the trunk, often roughened with darker, horizontal bands or wart-like excrescences, becoming thick and fissured, almost black at the base of old trunks.

WOOD.--Light, soft, weak, close-grained, not durable, light brown, with thin, whitish sapwood.

DISTRIBUTION.--Common throughout the state, but most abundant in the Upper Peninsula.

HABITAT.--Prefers moist, sandy soil and gravelly hillsides.

NOTES.--One of the first trees to cover burned-over lands. Grows rapidly. Usually short-lived. Propagated from seed or cuttings.

+SALICACEAE+

+Largetooth Aspen+

_Populus grandidentata Michx._

HABIT.--A medium-sized tree 30-50 feet high, with a slender trunk 12-20 inches in diameter; forming a loose, oval or rounded crown of slender, spreading branches and coarse spray.

LEAVES.--Alternate, simple, 3-5 inches long, two-thirds as broad; orbicular-ovate; coarsely and irregularly sinuate-toothed; thin and firm; dark green above, paler beneath, glabrous both sides; petioles long, slender, laterally compressed.

FLOWERS.--April, before the leaves; dioecious; the staminate in short-stalked catkins 1-3 inches long; the pistillate in loose-flowered, long-stalked catkins at first about the same length, but gradually elongating; calyx 0; corolla 0; stamens 6-12, with red anthers; stigmas 2, 2-lobed, red.

FRUIT.--May; 2-valved, conical, acute, hairy capsules 1/8 inch long, borne in drooping catkins 4-6 inches long; seeds minute, dark brown, hairy.

WINTER-BUDS.--Terminal bud 1/8 inch long, ovoid to conical, acute, light chestnut, puberulous, dusty-looking.

BARK.--Twigs greenish gray and at first hoary-tomentose, becoming lustrous, orange or red-brown and finally greenish gray; thick, dark red-brown or blackish at the base of old trunks, irregularly fissured, with broad, flat ridges.

WOOD.--Light, soft, weak, close-grained, light brown, with thin, whitish sapwood.

DISTRIBUTION.--A common tree in the northern portions of the Lower Peninsula, but rare in the Upper Peninsula.

HABITAT.--Prefers rich, moist, sandy soil; borders of swamps; river-banks; hillsides.

NOTES.--Grows rapidly in many soils. Easily transplanted. Short-lived. Useful for temporary effect. Propagated from seed or cuttings.

+SALICACEAE+

+Balm of Gilead. Balsam+

_Populus balsamifera L._

HABIT.--A tree 60-75 feet high, with a trunk diameter of 1-3 feet; forming a rather narrow, open, pyramidal crown of few, slender, horizontal branches.

LEAVES.--Alternate, simple, 3-6 inches long, about one-half as broad; ovate to ovate-lanceolate; finely crenate-serrate; thin and firm; lustrous, dark green above, paler beneath; petioles 1-1/2 inches long, slender, terete, smooth.

FLOWERS.--April, before the leaves; dioecious; the staminate in long-stalked catkins 3-4 inches long; the pistillate in loose-flowered, long-stalked catkins 4-5 inches long; calyx 0; corolla 0; stamens 20-30, with bright red anthers; ovary short-stalked; stigmas 2, wavy-margined.

FRUIT.--May-June; 2-valved, ovoid, short-pedicelled capsules 1/4 inch long, borne in drooping catkins 4-6 inches long; seeds light brown, hairy.

WINTER-BUDS.--Terminal bud about 1 inch long, ovoid, long-pointed, brownish, resin-coated, sticky, fragrant.

BARK.--Twigs red-brown, becoming dark orange, finally green-gray; thick, grayish on old trunks, and shallowly fissured into broad, rounded ridges, often roughened by dark excrescences.

WOOD.--Light, soft, weak, close-grained, light red-brown, with thick, nearly white sapwood.

DISTRIBUTION.--Occurs throughout the entire state, but is more abundant and of greater size in the northern portions.

HABITAT.--Prefers river bottom-lands and borders of swamps.

NOTES.--Rapid in growth. Spreads from the roots. Most useful for shelter belts. Easily transplanted. Propagated from cuttings.

+SALICACEAE+

+Hairy Balm of Gilead. Balsam+

_Populus candicans Ait._ [_Populus balsamifera candicans (Ait.) Gray_]

HABIT.--A tree 50-70 feet high, with a trunk diameter of 1-3 feet; more spreading branches than in _P. balsamifera_, forming a broader and more open crown.

LEAVES.--Resemble those of _P. balsamifera_, but more broadly heart-shaped and more coarsely serrate; more or less pubescent when young; petioles pubescent.

FLOWERS.--Similar to those of _P. balsamifera_.

FRUIT.--Similar to that of _P. balsamifera_.

WINTER-BUDS.--Terminal bud about 1 inch long, ovoid, long-pointed, dark red-brown, resinous throughout, viscid, very aromatic.

BARK.--Twigs reddish or olive-green, with occasional longitudinal gray lines, covered with a fragrant, gummy secretion, becoming gray-green; dark gray, rough, irregularly striate and firm on old trunks.

WOOD.--Resembles that of _P. balsamifera_, but is somewhat heavier.

DISTRIBUTION.--Indigenous to the northern portions of the state, but often cultivated and occasionally escaping in the southern portion.

HABITAT.--In a great variety of soils and situations.

NOTES.--Grows rapidly in all soils and situations. Suckers readily from the roots. Propagated from cuttings.

+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 massive, horizontal branches and stout, more or less angled branchlets.

LEAVES.--Alternate, simple, 3-6 inches long, nearly as broad; broadly deltoid-ovate; coarsely crenate-serrate above the entire base; thick and firm; lustrous, 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, shining, 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-shores; grows well in drier situations.

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

+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 buttressed 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 acuminate; finely but bluntly crenate-serrate; thick and firm; dark green and shining above, lighter and more or less lustrous 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, shining 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.

+JUGLANDACEAE+

+Butternut+

_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.

LEAVES.--Alternate, compound, 15-30 inches long. Leaflets 11-17, 2-4 inches long and one-half as broad; sessile, except the terminal; oblong-lanceolate; finely serrate; thin; yellow-green and rugose above, pale and soft-pubescent beneath. Petioles stout, hairy.

FLOWERS.--May, with the leaves; monoecious; the staminate in cylindrical, greenish, drooping catkins 3-5 inches long; calyx 6-lobed, borne on a hairy bract; corolla 0; stamens 8-12, with brown anthers; the pistillate solitary or several on a common peduncle, about 1/3 inch long, their bracts and bractlets sticky-hairy; calyx 4-lobed, hairy; corolla 0; styles 2; stigmas 2, fringed, spreading, bright red.

FRUIT.--October; about 2-1/2 inches long, cylindrical, pointed, greenish, sticky-downy, solitary or borne in drooping clusters of 3-5; nuts with rough shells, inclosing a sweet, but oily kernel; edible.

WINTER-BUDS.--Terminal bud 1/2-3/4 inch long, oblong-conical, obliquely blunt, somewhat flattened, brownish, pubescent.

BARK.--Twigs orange-brown or bright green, rusty-pubescent, becoming smooth and light gray; gray and smoothish on young trunks, becoming brown on old trunks, narrow-ridged, with wide furrows.

WOOD.--Light, soft, weak, coarse-grained, light brown, with thin, lighter colored sapwood.

DISTRIBUTION.--Of common occurrence in the southern half of the Lower Peninsula.

HABITAT.--Prefers low, rich woods; river-banks; low hillsides.

NOTES.--Leaves appear late and fall early. Pith chambered, chocolate-brown. Large trees usually unsound. Not easily transplanted.

+JUGLANDACEAE+

+Black Walnut+

_Juglans nigra L._

HABIT.--A large tree 60-80 feet high, with a massive trunk 2-5 feet in diameter; forming an open, capacious crown of heavy branches and coarse branchlets.

LEAVES.--Alternate, compound, 1-2 feet long. Leaflets 13-23, the terminal often lacking, 2-4 inches long and one-half as broad; sessile; ovate-lanceolate, taper-pointed; sharp-serrate; thin; yellow-green and glabrous above, lighter and soft-pubescent beneath. Petioles stout, pubescent. Foliage aromatic when bruised.

FLOWERS.--May, with the leaves; monoecious; the staminate in cylindrical, greenish, drooping catkins 3-5 inches long; calyx 6-lobed, borne on a hairy bract; corolla 0; stamens numerous, with purple anthers; the pistillate solitary or several on a common peduncle, about 1/4 inch long, their bracts and bractlets hairy; calyx 4-lobed, pubescent; corolla 0; styles and stigmas 2.

FRUIT.--October; globose, 1-1/2-2 inches in diameter, smooth, not viscid; solitary or borne in clusters of 2-3; nuts with irregularly furrowed shell, inclosing a sweet, edible kernel.

WINTER-BUDS.--Terminal bud 1/3 inch long, ovoid, obliquely blunt, slightly flattened, silky-tomentose.

BARK.--Twigs brownish and hairy, becoming darker and smooth; thick, brownish or blackish on the trunk and deeply furrowed by broad, rounded ridges.

WOOD.--Heavy, hard, strong, close-grained, very durable in contact with the soil, rich dark brown, with thin, lighter colored sapwood.

DISTRIBUTION.--Lower Peninsula as far north as Bay City, but more abundant in the southern portion of its range.

HABITAT.--Prefers rich bottom-lands and fertile hillsides.

NOTES.--Leaves appear late and fall early. Fruit very aromatic. Pith chambered, cream colored. The juices from the husk stain the hands brown. Not easily transplanted. Often infested with caterpillars.

+SUMMER KEY TO THE SPECIES OF CARYA+

a. Bark of trunk essentially smooth, not deeply furrowed nor shaggy; husk of fruit less than 1/8 inch thick.

b. Leaflets usually 5-7, glabrous beneath; buds dome-shaped, greenish; kernel of nut sweet.

c. Twigs long-hairy; fruit less than 1 inch long. _C. microcarpa_, p. 75.

cc. Twigs glabrous or nearly so; fruit 1-1/2-2 inches long. _C. glabra_, p. 77.

bb. Leaflets usually 7-11, more or less downy beneath; buds elongated, bright yellow; kernel of nut bitter. _C. cordiformis_, p. 79.

aa. Bark of trunk deeply furrowed or shaggy; husk of fruit more than 1/8 inch thick.

b. Twigs more or less pubescent; leaflets 5-7, more or less pubescent beneath.

c. Twigs brownish; buds densely hairy; fruit 1-1/2-2 inches long. _C. alba_, p. 73.

cc. Twigs orange; buds merely puberulous; fruit 1-3/4-2-1/2 inches long; (leaflets usually 7). _C. laciniosa_, p. 71.

bb. Twigs tending to be glabrous; leaflets usually 5, glabrous beneath. _C. ovata_, p. 69.

+WINTER KEY TO THE SPECIES OF CARYA+

a. Bark of trunk essentially smooth, not deeply furrowed nor shaggy; husk of fruit less than 1/8 inch thick.

b. Terminal bud narrow, long-pointed, flattish, bright yellow; kernel of nut bitter. _C. cordiformis_, p. 79.

bb. Terminal bud broad, dome-shaped, not bright yellow; kernel of nut sweet.

c. Buds greenish; twigs glabrous; fruit 1-1/2-2 inches long. _C. glabra_, p. 77.