Chapter I: Front Matter (1)

Forest Trees
of Illinois

THIRD EDITION

By Robert H. Mohlenbrock
Department of Botany, Southern Illinois University

Photography by John A. Richardson and Robert H. Mohlenbrock
Illustrations by Miriam Wysong Meyer and Fredda J. Burton
Southern Illinois University

Printed by authority of the State of Illinois
Issued by
DEPARTMENT OF CONSERVATION
Division of Forestry

14
(17943—10M—4-80)

TABLE OF CONTENTS

Acknowledgments 4
Introduction 5
Illustrated Glossary 6
Key to the Trees of Illinois in Spring, Summer, and Fall 9
Key to the Trees of Illinois in Winter 27
Trees of Illinois 38
Special Places to Study Trees 318
White Oak, the State Tree of Illinois 322
Illinois Big Tree Champions 323
Index to Common and Scientific Names 324
District Foresters 330

Acknowledgments

I am grateful to the late Mr. Fred Siemert, State Forester of the Illinois Division of Forestry, for suggesting the need for a new “Forest Trees of Illinois.” The first and second editions of this work have been immensely popular, and the need for a third edition is gratifying.

This third edition is only slightly modified from the second. A few illustrations and bark photographs have been substituted, and the key has been improved in places. New material has been added to the description of the water hickory.

I wish to give thanks to Mr. Al Mickelson of the Illinois Division of Forestry for encouraging this third edition, and to his assistants, Mr. John Sester and Mr. Ernest Kunze, for editing it for publication. Mark Mohlenbrock has redrawn the leaves and fruit illustrated on pages 101 and 169.

Introduction

The initial edition of Forest Trees of Illinois was written in 1927 by W. R. Mattoon and R. B. Miller, two prominent foresters in the state at that time. This was revised in 1955 by Dr. George Damon Fuller, then of the Illinois State Museum, and E. E. Nuuttila, State Forester of Illinois.

In 1973, I prepared the first edition of the new Forest Trees of Illinois with new text, keys, photographs, and illustrations. An updated second edition was published in 1978. Because of the heavy demand for this work, this third edition has been prepared.

Woody plants are usually divided into trees and shrubs, but the difference between these growth forms is not always distinct. In this work, we consider a plant to be of tree stature if it has a single erect trunk which branches above the ground to form a crown. It must have a diameter of at least 3 inches 4½ feet above the ground and an overall height of 12 feet. Some of the plants included in this work are borderline between trees and shrubs. The height of a plant may be influenced by its geography. Thus, the Gray Dogwood (_Cornus racemosa_) in extreme southern Illinois may reach the dimensions of a small tree, but this same species in northern Illinois is also of a shrubby stature.

Almost every kind of plant in the world is known by a Common Name and a Latin Name. The Common Name is the one used locally by residents of the area. It is of limited value because people in different areas sometimes have different names for the same plant. For example, one of the trees in Illinois is known by some as the Ironwood, by others as the Blue Beech, by others as the American Hornbeam, and by still others as the Musclewood Tree. Then again, the name Ironwood applies to at least two different kinds of trees in Illinois. The Latin Name for each kind of tree is known the World over by the same name. Actually, the Latin Name is composed of two words, the genus name, which is always capitalized, and the specific epithet, which is not capitalized.

Of all the kinds of plants in the World, none is so well-loved, so stately and majestic, as a forest tree. More and more people each year are vacationing and seeking outdoor recreation. Many of them “take to the woods” for their leisure, because the forests of our state hold an unending fascination to many who enter them.

Moreover, trees provide us with building material for our homes, shade for our lawns and parks, and hundreds of other products used in our everyday living.

To know the trees we encounter is to enhance our appreciation for them. The purpose of FOREST TREES OF ILLINOIS is to bring to Illinoisans a means of identifying the trees that grow in this state.

Illustrated Glossary

In order to distinguish one kind of tree from another, it is necessary to learn the major characteristics which the forest trees of Illinois may possess. Illustrated below are several of the most commonly encountered characteristics of leaves and twigs. A thorough understanding of these structures will insure a quicker and more accurate identification.

On the pages following the illustrated glossary are keys to the trees of Illinois. A key is a botanical device which enables the user, through proper selection of a series of choices, to identify a specimen at hand. Separate keys are provided for trees during the spring, summer, and autumn seasons and during the winter season. Begin at the first pair of number 1’s, choose the statement that best fits the unknown specimen, and then go to the next pair of statements beneath. Continue this same procedure until the name of the plant is reached.

LEAF FORMS AND ARRANGEMENT
SIMPLE
PINNATELY COMPOUND
PALMATELY COMPOUND
DOUBLY PINNATELY COMPOUND
OPPOSITE
ALTERNATE
WHORLED
LEAF SHAPES
LANCEOLATE
OBLANCEOLATE
OBLONG
ELLIPTICAL
OVATE
OBOVATE

WINTER TWIG CHARACTERS
BUD SCALE
TERMINAL BUD
LATERAL BUD
LEAF SCAR
LENTICELS
BUNDLE TRACES
{LEAF LAYERS}
UPPER EPIDERMIS
PALISADE LAYER
RIBS AND VEINS
SPONGY LAYER
STOMA
LOWER EPIDERMIS
LEAF TIPS
ACUTE
OBTUSE
LONG-TAPERING
LEAF EDGES
PINNATELY LOBED
WAVY
TOOTHED
DOUBLY TOOTHED
SMOOTH
LEAF BASES
HEART-SHAPED
TRUNCATE
ASYMMETRICAL
ROUNDED
TAPERING

Key to the Trees of Illinois in Spring, Summer, and Fall

1. Leaves needle-like or scale-like Group A
1. Leaves broad and flat, never needle-like or scale-like.
2. Leaves compound (divided into 3 or more leaflets) Group B
2. Leaves simple.
3. Leaves opposite or whorled Group C
3. Leaves alternate.
4. Leaves neither toothed nor lobed Group D
4. Leaves toothed or lobed or both.
5. Leaves toothed but not lobed Group E
5. Leaves lobed Group F

GROUP A

Leaves needle-like or scale-like, often evergreen.

1. Leaves in clusters of 2 or more.
2. Leaves in clusters of 10 or more, falling off during autumn.
3. Leaves blue-green; cone-scales smooth _Larix laricina_
3. Leaves bright green; cone-scales hairy _Larix decidua_
2. Leaves in clusters of 2-5, evergreen.
4. Leaves in clusters of 5 _Pinus strobus_
4. Leaves in clusters of 2-3.
5. Leaves in clusters of 2.
6. Most or all the leaves less than 3 inches long, usually
twisted.
7. Leaves up to 1½ inches long; sheath at base of leaves not
longer than ⅛ inch _Pinus banksiana_
7. Leaves 2-3 inches long; sheath at base of leaves at least
⅓ inch long _Pinus sylvestris_
6. Most or all the leaves longer than 3 inches, rarely
twisted.
8. Leaves mostly less than 5 inches long; cone-scale with a
small spine _Pinus echinata_
8. Leaves mostly more than 5 inches long; cone-scale without
a spine _Pinus resinosa_
5. Leaves in clusters of 3.
9. Leaves flexible, mostly less than 5 inches long; sheath at
base of leaves about ¼ inch long _Pinus echinata_
9. Leaves stiff, mostly more than 5 inches long; sheath at
base of leaves about 1 inch long _Pinus taeda_
1. Leaves solitary.
10. Leaves evergreen, of 2 types, some of them scale-like and about
⅛ inch long, some of them needle-like and up to ⅓ inch long
_Juniperus virginiana_
10. Leaves falling off in autumn, all needle-like, usually at least
½ inch long.
11. Leaves 3-angled.
12. Leaves blue-green _Larix laricina_
12. Leaves bright green _Larix decidua_
11. Leaves flat _Taxodium distichum_

GROUP B

Leaves broad and flat, never needle-like or scale-like, compound.

1. Leaves alternate.
2. Leaflets 3 _Ptelea trifoliata_
2. Leaflets 5 or more.
3. Main stalk between leaflets winged on either side
_Rhus copallina_
3. Main stalk between leaflets not winged.
4. Leaves with an even number of leaflets, often doubly
compound.
5. Leaflets not more than ½ inch wide.
6. Pods usually 12 inches long or longer, with 6 or more
seeds _Gleditsia triacanthos_
6. Pods 1-2 inches long, with 1-3 seeds _Gleditsia aquatica_
5. Some or all the leaflets at least one inch broad.
7. Leaves doubly compound; leaflets smooth along the edges;
leaves without a foul odor when crushed
_Gymnocladus dioicus_
7. Leaves once compound; leaflets usually with a few coarse
teeth along the edges; leaves with a foul odor when
crushed _Ailanthus altissima_
4. Leaves with an odd number of leaflets, once compound (twice
compound in _Aralia spinosa_, which has prickly leafstalks).
8. Leaflets without teeth along the edges.
9. Leaflets less than 1 inch broad and 2 inches long; twigs
with short spines at base of leaf stalks
_Robinia pseudoacacia_
9. Leaflets up to 4 inches long and up to 2 inches broad;
twigs without spines.
10. Some or all the leaflets alternate; base of leafstalk
conspicuously swollen _Cladrastis lutea_
10. All the leaflets opposite; base of leafstalk not
swollen _Rhus vernix_
8. Leaflets toothed along the edges.
11. Leaves doubly compound, often with small prickles on the
leafstalks and on some of the veins _Aralia spinosa_
11. Leaves once compound, without prickles.
12. All leaves with 11 or more leaflets.
13. Leafstalks and lower surface of leaves completely
smooth _Rhus glabra_
13. Leafstalks and lower surface of leaves (at least on
the veins) hairy.
14. Pith of twigs chambered when cut lengthwise.
15. Pith pale brown; bark dark brown, with roughened
ridges _Juglans nigra_
15. Pith dark brown; bark gray, with smooth ridges
_Juglans cinerea_
14. Pith of twigs solid.
16. Leaves strongly aromatic when crushed; twigs not
covered with velvety hairs.
17. Bud scales with yellow hairs; nut 1½ to 2
times longer than broad _Carya illinoensis_
17. Bud scales without yellow hairs; nut about as
broad as long _Carya aquatica_
16. Leaves not aromatic when crushed; twigs covered
with velvety hairs _Rhus typhina_
12. Some or all leaves with less than 11 leaflets.
18. Buds with 4-6 scales arranged in pairs; most of the
leaves with at least 9 leaflets.
19. Terminal leaflet without a stalk or with a very
short stalk; buds mustard-yellow
_Carya cordiformis_
19. Terminal leaflet with a well-developed stalk; bud
reddish-brown _Carya aquatica_
18. Buds with 6 or more overlapping scales; most of the
leaves with fewer than 9 leaflets (except sometimes
in _Carya tomentosa_ and _Carya laciniosa_), never
with 11 leaflets.
20. Teeth along the leaf margin with small tufts of
hairs _Carya ovata_
20. Teeth along the leaf margin without small tufts of
hairs.
21. Lower surface of leaflets densely and uniformly
hairy.
22. Stalk to which leaflets are attached densely
hairy; bark tight, not shaggy
_Carya tomentosa_
22. Stalk to which leaflets are attached smooth or
sparsely hairy; bark shaggy at maturity
_Carya laciniosa_
21. Lower leaf surface smooth, or with tufts of
hairs in the vein axils, or sometimes sparsely
hairy along the veins.
23. Scales of buds, stalk of leaves, and young
twigs rusty-hairy or -scaly _Carya texana_
23. Rusty hairs and scales not present.
24. Leaflets mostly 5; bud scales without hairs
at the tip; bark tight, not peeling
_Carya glabra_
24. Leaflets mostly 7; bud scales with hairs at
the tip; bark peeling at maturity
_Carya ovalis_
1. Leaves opposite.
25. Leaves palmately compound.
26. Leaflets mostly 7; buds very sticky _Aesculus hippocastanum_
26. Leaflets mostly 5; buds not sticky.
27. Fruit prickly; flowers yellow _Aesculus glabra_
27. Fruit smooth; flowers red _Aesculus discolor_
25. Leaves pinnately compound, or sometimes with only 3 leaflets.
28. Leaflets usually 3, or sometimes 5; twigs green or glaucous
_Acer negundo_
28. Leaflets usually 7 or more, sometimes 5; twigs not green.
29. Some or all of the twigs square _Fraxinus quadrangulata_
29. Stems not square.
30. Leaflets without stalks _Fraxinus nigra_
30. Leaflets stalked.
31. Stalks of the leaflets winged.
_Fraxinus pennsylvanica_ var. _subintegerrima_
31. Twigs and leafstalks smooth
32. Leaflets whitened on the lower surface
_Fraxinus americana_
32. Leaflets green or yellow-brown on the lower surface
_Fraxinus tomentosa_

GROUP C

Leaves broad and flat, never needle-like or scale-like, simple, opposite or whorled.

1. Leaves (or some of them) in whorls of 3.
2. Leaves with a bad odor when crushed; flowers with conspicuous
purple spots _Catalpa bignonioides_
2. Leaves without a bad odor when crushed; flowers merely lined with
purple _Catalpa speciosa_
1. Leaves opposite.
3. Leaves at least 6 inches long and 6 inches broad, heart-shaped at
the base, never palmately lobed _Paulownia tomentosa_
3. Leaves usually less than 6 inches long and 6 inches broad, not
heart-shaped at the base or, if slightly heart-shaped, then also
palmately lobed.
4. Leaves palmately lobed.
5. Leafstalk with milky sap when broken _Acer platanoides_
5. Leafstalk without milky sap.
6. Areas between leaf lobes mostly V-shaped; leaves usually
silvery or white on the lower surface.
7. Leaves deeply divided, the areas between the lobes
extending more than half-way to the midvein
_Acer saccharinum_
7. Leaves shallowly divided, the areas between the lobes
extending less than half-way to the midvein.
8. Leaves completely covered with a white felt on the
lower surface _Acer rubrum var. drummondii_
8. Leaves smooth or sparsely hairy on the lower leaf
surface _Acer rubrum_
6. Areas between leaf lobes mostly U-shaped; leaves green or
paler on the lower surface, not white or silvery.
9. Leaves with the edges drooping.
10. Leaves green on the lower surface; small leafy
outgrowths sometimes present at the base of the
leafstalk _Acer nigrum_
10. Leaves grayish on the lower surface; small leafy
outgrowths at the base of the leafstalk absent
_Acer barbatum_
9. Leaves flat, the edges not drooping _Acer saccharum_

4. Leaves not lobed.
11. Leaves toothed along the edges.
12. Edges of leaves regularly toothed from tip of leaf to
base; leaves usually short-pointed or rounded at the tip.
13. Buds, leafstalks, and veins on the lower surface of the
leaf covered with rusty hairs _Viburnum rufidulum_
13. Buds, leafstalks, and veins on the lower surface of the
leaf without rusty hairs.
14. Leaf stalks wavy along the edges _Viburnum lentago_
14. Leaf stalks not wavy along the edges.
15. Branches spine-tipped _Rhamnus cathartica_
15. Branches not spine-tipped _Viburnum prunifolium_
12. Edges of leaves toothed only above the middle of the leaf;
leaves tapering to a long point _Forestiera acuminata_
11. Leaves not toothed along the edges.
16. Upper surface of leaves rough to the touch
_Cornus drummondii_
16. Upper surface of leaves smooth.
17. Leaves with deeply impressed veins on the upper surface;
lower surface of leaves gray or whitish.
18. Leaves often nearly as broad as long; flowers
surrounded by 4 large, white bracts; berries red;
twigs green _Cornus florida_
18. Leaves longer than broad; flowers not surrounded by 4
large, white bracts; berries white; twigs gray
_Cornus racemosa_
17. Leaves without deeply impressed veins; leaves often
paler on the lower surface, but not gray or whitish
_Forestiera acuminata_

GROUP D

Leaves broad and flat, never needle-like or scale-like, simple, alternate, neither toothed nor lobed.

1. Most or all of the leaves more than six inches long.
2. Leaves long-tapering to the base; winter buds elongated, about ⅛
inch long, covered with reddish-brown hairs _Asimina triloba_
2. Leaves rounded or only short-tapering to the base; winter buds
either ½ inch long and white-hairy, or rounded and yellow.
3. Leafstalks usually more than 1½ inches long, hairy; buds nearly
round, yellow _Nyssa aquatica_
3. Leafstalks usually less than 1½ inches long, smooth; buds
elongated, white-hairy _Magnolia acuminata_
1. Most or all of the leaves less than six inches long.
4. Leafstalks with milky sap; twigs usually bearing small spines
near the point of the leaf attachment _Maclura pomifera_
4. Leafstalks without milky sap; twigs not spiny.
5. Leaves spicy-aromatic when crushed, twigs green
_Sassafras albidum_
5. Leaves not spicy-aromatic when crushed; twigs usually not
green.
6. Leaves distinctly asymmetrical at base, usually obviously
3-nerved from the base.
7. Leaves usually at least twice longer than broad, rounded at
the base _Celtis laevigata_
7. Leaves usually less than twice longer than broad, more or
less heart-shaped at the base _Celtis tenuifolia_
6. Leaves symmetrical at the base, with a single main vein.
8. Leaves heart-shaped at the base, about as broad as long
_Cercis canadensis_
8. Leaves rounded or tapering to the base, longer than broad.
9. Many of the leaves clustered near the tips of the twigs.
10. Leaves abruptly short-pointed at the tip
_Nyssa sylvatica_
10. Leaves tapering to the tip.
11. Veins of leaf deeply impressed, strongly arching
toward the tip of the leaf; fruit a berry
_Cornus alternifolia_
11. Veins of leaf not deeply impressed nor strongly
arching toward the tip of the leaf; fruit an acorn.
12. Lower surface of leaves hairy; leafstalk usually
hairy; leaves usually one inch wide or wider
_Quercus imbricaria_
12. Lower surface of leaves smooth except for the
veins; leafstalk usually smooth; leaves usually
less than one inch wide _Quercus phellos_
9. Leaves not clustered near the tips of the twigs.
13. Leaves usually with 10 or more pairs of veins;
leafstalks often 1½ inches long or longer
_Nyssa aquatica_
13. Leaves usually with 6-8 pairs of veins; leafstalks
rarely as long as 1½ inches.
14. Leaves abruptly contracted to a short point at the
tip.
15. Leaves usually about twice as long as broad; fruit
an orange berry about 1 inch in diameter
_Diospyros virginiana_
15. Leaves usually less than twice as long as broad;
fruit a blue berry up to ½ inch in diameter
_Nyssa sylvatica_
14. Leaves gradually tapering to the tip
_Rhamnus caroliniana_

GROUP E

Leaves broad and flat, never needle-like or scale-like; leaves simple, alternate, toothed but not lobed.

1. Leaves asymmetrical at the base.
2. Leaves with 3 main veins arising from the base of the blade.
3. Edge of leaf with low, rounded teeth or merely wavy
_Hamamelis virginiana_
3. Edge of leaf sharply or finely toothed.
4. Most of all the leafstalks less than one inch long; trunk
usually warty.
5. Upper surface of leaf very rough to the touch; leaves thick
and leathery.
6. Leaves tapering to a long point at the tip; most or all
of the blades 3 inches long or longer
_Celtis occidentalis_
6. Leaves tapering to a short point at the tip; most or all
of the blades less than 3 inches long
_Celtis tenuifolia_
5. Upper surface of leaf smooth or only slightly rough to the
touch; leaves thin and membranaceous.
7. Leaves at least three times longer than broad
_Celtis laevigata_
7. Leaves less than three times longer than broad.
8. Some or all the leaves 3 inches long or longer
_Celtis occidentalis_
8. Leaves less than 3 inches long _Celtis tenuifolia_
4. Leafstalks more than 1 inch long.
9. Leaves smooth on the lower surface except for small tufts
of hairs where the veins meet _Tilia americana_
9. Leaves hairy on the lower surface.
10. Lower surface of leaves white _Tilia heterophylla_
10. Lower surface of leaves green _Tilia americana_

2. Leaves with one main vein arising from the base of the blade.
11. Some of the twigs with corky wings.
12. Some or all the leaves four inches long or longer;
leaf-stalks more than ⅛ inch long _Ulmus thomasii_
12. None of the leaves four inches long; leafstalks up to ⅛ inch
long _Ulmus alata_
11. Twigs without corky wings.
13. Leaves very rough-hairy to the touch _Ulmus rubra_
13. Leaves smooth or soft to the touch.
14. Edge of leaf doubly toothed (each tooth divided into a
second small tooth).
15. Leaves distinctly one-sided at the base; leafstalks
often smooth _Ulmus americana_
15. Leaves only slightly one-sided at the base; leafstalks
hairy.
16. Bark of trunk with sinewy ridges; fruit enclosed in
flat, 3-lobed bracts; lower lateral veins of leaf
unbranched _Carpinus caroliniana_
16. Bark of trunk broken into scales; fruit surrounded by
inflated, bladdery bracts; lower lateral veins of leaf
branched _Ostrya virginiana_
14. Edge of leaf singly toothed.
17. Leaves smooth on the lower surface; leafstalks smooth
_Ulmus pumila_
17. Leaves hairy on the lower surface, at least where the
veins meet; leafstalks usually hairy _Planera aquatica_
1. Leaves symmetrical at the base.
18. Leaves with 2-4 irregular teeth along the edges.
19. Leaves usually with 10 or more pairs of veins; leaf stalks
often 1½ inches long or longer _Nyssa aquatica_
19. Leaves usually with 6-8 pairs of veins; leaf stalks rarely as
long as 1½ inches _Nyssa sylvatica_
18. Leaves more regularly toothed with more than 4 teeth along the
edges.
20. Leafstalks with milky sap when broken.
21. Leaf stalks and lower surface of leaf with long hairs
_Broussonetia papyrifera_
21. Leaf stalks and lower surface of leaf smooth or with short
hairs.
22. Lower leaf surface hairy between the veins _Morus rubra_
22. Lower leaf surface smooth or hairy only on the veins
_Morus alba_
20. Leafstalks without milky sap when broken.
23. Leaves at least 4 times as long as broad.
24. Leafstalks less than ⅛ inch long; leaves irregularly
toothed along the edges _Salix interior_
24. Leafstalks more than ⅛ inch long; leaves regularly toothed
along the edges.
25. Leaves green on the lower surface _Salix nigra_
25. Leaves whitish on the lower surface.
26. Each leaf with a pair of leaf-like stipules at the
base of the leafstalk _Salix caroliniana_
26. Each leaf without a pair of leaf-like stipules
_Salix amygdaloides_
23. Leaves less than 4 times as long as broad.
27. Leaves as broad as long or broader.
28. Leaf stalks not flattened.
29. Leaves strongly whitened on the lower surface, not
heart-shaped at the base _Populus alba_
29. Leaves not strongly whitened on the lower leaf
surface, heart-shaped at the base
_Populus heterophylla_
28. Leaf stalks flattened.
30. Leaves basically triangular in shape, coarsely toothed
_Populus deltoides_
30. Leaves basically ovate or spherical, coarsely or
finely toothed.
31. Leaves with 20 or more fine teeth along the edges
_Populus tremuloides_
31. Leaves with up to 15 coarse teeth along the edges.
_Populus grandidentata_
27. Leaves longer than broad.
32. Twigs usually with sharp spines.
33. Leaves broadest below the middle; fruit a small apple.
34. Many of the leaves narrowly oblong to narrowly
elliptic _Malus angustifolia_
34. Most of the leaves ovate to oval to broadly
lance-shaped.
35. Twigs and young leaves densely hairy
_Malus ioensis_
35. Twigs and young leaves smooth or nearly so
_Malus coronaria_
33. Leaves broadest at or above the middle; fruit a
hawthorn.
36. Leaves broadest at the middle; leafstalks one inch
long or longer _Crataegus viridis_
36. Leaves broadest above the middle; leafstalks up to ¾
inch long.
37. Leaves leathery, smooth on both surfaces
_Crataegus crus-galli_
37. Leaves not leathery, usually somewhat hairy on the
lower surface _Crataegus punctata_
32. Twigs not spiny.
38. Some of the twigs with corky wings.
39. Some or all the leaves 4 inches long or longer;
leafstalks more than ⅛ inch long _Ulmus thomasii_
39. None of the leaves 4 inches long; leafstalks up to ⅛
inch long _Ulmus alata_
38. None of the twigs with corky wings.
40. Individual teeth along edge of the leaf at least ¼
inch long.
41. Most of the veins not reaching to the tip of each
leaf; lower surface of leaf usually silvery-white
_Quercus bicolor_
41. Most of the veins projecting to the tip of each
leaf; lower surface of leaf green or pale, but
usually not silvery-white.
42. Leaves usually with sharp-pointed teeth.
43. Fruit an acorn; lower leaf surface usually
covered with very short hairs
_Quercus muhlenbergii_
43. Fruit enclosed in a prickly bur; lower leaf
surface smooth or nearly so _Castanea dentata_
42. Leaves usually with somewhat rounded teeth.
44. Cup of acorn at least 1 inch across; trunk
whitish to gray _Quercus michauxii_
44. Cup of acorn less than 1 inch across; trunk
brown to black _Quercus prinus_
40. Individual teeth along edge of leaf up to ⅛ inch
long.
45. Some of the leaves produced from short, stubby
shoots along the main twigs _Ilex decidua_
45. Twigs without short, stubby side shoots.
46. Leafstalks with 1 or more small glands
(“bumps”), usually near the point of attachment
to the blade.
47. Each tooth along the edge of the leaf bearing
a small, reddish-brown gland.
48. Some or all leaves one inch broad or
broader.
49. Leaves flat _Prunus hortulana_
49. Leaves more or less folded down the middle
_Prunus munsoniana_
48. None of the leaves as much as one inch broad
_Prunus angustifolia_
47. Teeth along the edge of the leaf not bearing a
gland.
50. Leaves usually with a dull, wrinkled
surface; fruit a plum _Prunus americana_
50. Leaves usually appearing smooth and rather
shiny; fruit an elongated cluster of small
cherries.
51. Teeth along edge of leaf curving inward,
usually rather blunt _Prunus serotina_
51. Teeth along edge of leaf pointing outward,
usually sharp-pointed _Prunus virginiana_
46. Leafstalks not bearing glands.
52. Leaves doubly toothed along the edges.
53. Bark peeling off into papery strips or
layers; leaves usually about two-thirds as
broad as long or broader.
54. Bark yellowish, silvery-gray, or
creamy-white.
55. Bark yellowish or silvery-gray; leaves
with 8 or more pairs of veins
_Betula lutea_
55. Bark creamy-white; leaves with no more
than 7 pairs of veins
_Betula papyrifera_
54. Bark reddish-brown _Betula nigra_
53. Bark broken into small plates, or smooth and
sinewy, not peeling off into papery strips
or layers.
56. Bark of trunk with sinewy ridges; fruit
enclosed in flat, 3-lobed bracts; lower
lateral veins of leaf unbranched
_Carpinus caroliniana_
56. Bark of trunk broken into scales; fruit
enclosed in inflated, bladdery bracts;
lower lateral veins of leaf branched
_Ostrya virginiana_
52. Leaves singly toothed along the edges.
57. Leaves heart-shaped at the base.
58. Leaves up to six inches long and nearly as
broad _Populus heterophylla_
58. Leaves not more than four inches long and
about half as broad.
59. Leaves bronze as they unfold; leafstalk
smooth _Amelanchier laevis_
59. Leaves densely white-hairy as they
unfold; leafstalk somewhat hairy
_Amelanchier arborea_
57. Leaves rounded or tapering to the base, not
heart-shaped.
60. Teeth along edge of leaf widely spaced, at
least ¼ inch apart _Fagus grandifolia_
60. Teeth along edge of leaf closely and
regularly spaced.
61. Leafstalk hairy; fruit fleshy.
62. Leaves shiny on the upper surface;
leafstalks ½ inch long or longer
_Rhamnus caroliniana_
62. Leaves dull on the upper surface;
leafstalks up to ¼ inch long
_Planera aquatica_
61. Leafstalk smooth at maturity; fruit dry
and variously winged.
63. Some of the leaves three inches long
or longer; fruit 4-winged or a woody
“cone.”
64. Leaves pointed at the tip; fruit
4-winged _Halesia carolina_
64. Leaves rounded at the tip; fruit a
woody “cone” _Alnus glutinosa_
63. Leaves less than 3 inches long; fruit
surrounded by a flat wing
_Ulmus pumila_

GROUP F

Leaves broad and flat, never needle-like or scale-like; leaves simple, alternate, lobed.

1. Leafstalks with milky sap when broken.
2. Leafstalks and lower surface of leaf with long hairs
_Broussonetia papyrifera_
2. Leafstalks and lower surface of leaf smooth or with short hairs.
3. Lower leaf surface hairy between the veins _Morus rubra_
3. Lower leaf surface smooth or hairy only on the veins
_Morus alba_
1. Leafstalks without milky sap when broken.
4. Twigs usually with sharp spines.
5. Leaves broadest at the middle or above the middle.
6. Leaves broadest at the middle; lower surface of leaf smooth
except for a few tufts of hairs near the veins
_Crataegus viridis_
6. Leaves broadest above the middle; lower surface of leaf hairy
throughout _Crataegus punctata_
5. Leaves broadest below the middle.
7. Leaves hairy throughout on the lower surface.
8. Leaves mostly tapering to the base; fruit a crab apple
_Malus ioensis_
8. Leaves rounded at the base; fruit a hawthorn.
9. Fruit with pitted seeds; flowers appearing in late May
and June _Crataegus calpodendron_
9. Fruit without pitted seeds; flowers appearing in April or
early May _Crataegus mollis_
7. Leaves smooth on the lower surface or hairy only on the
veins.
10. Leaves tapering to the base.
11. Leaves oval to ovate to broadly lance-shaped
_Malus coronaria_
11. Leaves narrowly oblong to narrowly elliptic
_Malus angustifolia_
10. Leaves rounded at the base.
12. Leaves blue-green; fruit spherical or nearly so
_Crataegus pruinosa_
12. Leaves green; fruit shaped like a little apple
_Malus coronaria_
4. Twigs without spines.
13. Leaves star-shaped _Liquidambar styraciflua_
13. Leaves not star-shaped.
14. Leaves 4-lobed, smooth on both surfaces
_Liriodendron tulipifera_
14. Leaves more than 4-lobed, hairy on one or both surfaces.
15. Leaves palmately lobed and veined.
16. Leaves densely coated with white felt on the lower
surface _Populus alba_
16. Leaves without a coat of white felt on the lower surface
_Platanus occidentalis_
15. Leaves pinnately lobed and veined.
17. Lobes of leaf with bristle-tips.
18. Leaves broadest above the middle _Quercus marilandica_
18. Leaves broadest at or below the middle.
19. Leaves hairy throughout on the lower surface.
20. Lower surface of leaves with gray hairs; base of
leaf blade usually broadly rounded.
21. Leaves with 5-11 more or less equal lobes, the
uppermost lobe not strongly curved
_Quercus pagodaefolia_
21. Leaves with 3-5 more or less unequal lobes, the
uppermost lobes often strongly curved
_Quercus falcata_
20. Lower surface of leaves with rusty hairs; base of
leaf blade not broadly rounded _Quercus velutina_
19. Leaves smooth on the lower surface or hairy only
next to the veins.
22. Leaves divided less than halfway to the middle.
23. Leafstalks hairy; buds hairy, gray
_Quercus velutina_
23. Leafstalks smooth; buds smooth, reddish-brown
_Quercus rubra_
22. Leaves divided more than halfway to the middle.
24. Leafstalks hairy; cup of acorn fringed around
the edge _Quercus velutina_
24. Leafstalks smooth; cup of acorn not fringed
around the edge.
25. Lower surface of leaves with large tufts of
hairs in the vein axils.
26. Cup of acorn saucer-shaped.
27. Cup of acorn up to ½ inch broad.
_Quercus palustris_
27. Cup of acorn more than ½ inch broad
_Quercus shumardii_
26. Cup of acorn top-shaped.
28. Cup of acorn enclosing about ⅓ the nut at
most _Quercus shumardii_
28. Cup of acorn enclosing more than one-third
of the nut _Quercus ellipsoidalis_
25. Lower surface of leaves smooth or with small
tufts in hairs in the vein axils
_Quercus coccinea_
17. Lobes of leaf with round tips, not bristle-tipped.
29. Leaves smooth on the lower surface _Quercus alba_
29. Leaves hairy on the lower surface.
30. Upper three lobes of leaf squarish, forming a cross;
twigs hairy _Quercus stellata_
30. Leaves without three squarish lobes at the upper
end; twigs smooth or nearly so.
31. Edge of acorn cup with a fringe
_Quercus macrocarpa_
31. Edge of acorn cup not fringed _Quercus lyrata_

Key to Illinois Trees in Winter

1. Green leaves present during winter, needle-like or scale-like
Group G
1. Green leaves absent during winter Group H

GROUP G

1. Leaves in clusters of 2 or more.
2. Leaves in clusters of 5 _Pinus strobus_
2. Leaves in clusters of 2-3.
3. Leaves in clusters of 2.
4. Most or all the leaves less than 3 inches long, usually
twisted.
5. Leaves up to 1½ inches long; sheath at base of leaves not
longer than ⅛ inch _Pinus banksiana_
5. Leaves 2-3 inches long; sheath at base of leaves at least ⅓
inch long _Pinus sylvestris_
4. Most or all the leaves longer than 3 inches, rarely twisted.
6. Leaves mostly less than 5 inches long; cone-scale with a
small spine _Pinus echinata_
6. Leaves mostly more than 5 inches long; cone-scale without a
spine _Pinus resinosa_
3. Leaves in clusters of 3.
7. Leaves flexible, mostly less than 5 inches long; sheath at
base of leaves about ¼ inch long _Pinus echinata_
7. Leaves stiff, mostly more than 5 inches long; sheath at base
of leaves about 1 inch long _Pinus taeda_
1. Leaves solitary, of 2 types, some of them scale-like and about ⅛
inch long, some of them needle-like and up to ⅓ inch long
_Juniperus virginiana_

GROUP H

1. Leaf scars absent (scars which resemble leaf scars present but
lacking bundle scars) _Taxodium distichum_
1. Leaf scars present.
2. Leaf scars in whorls of 3 _Catalpa spp._
2. Leaf scars opposite or alternate.
3. Leaf scars opposite.
4. Bundle scar 1 _Forestiera acuminata_
4. Bundle scars 3 or more.
5. Bundle scars usually 9 or more.
6. Pith hollow or sometimes chambered _Paulownia tomentosa_
6. Pith solid, not chambered.
7. Twigs 4-sided _Fraxinus quadrangulata_
7. Twigs not 4-sided.
8. Twigs hairy.
9. Leaf scars notched at top.
10. Twigs with conspicuous large lenticels; trunks
swollen at the base _Fraxinus tomentosa_
10. Twigs with inconspicuous lenticels; trunks not
swollen at the base _Fraxinus americana_
9. Leaf scars more or less straight across at the top
_Fraxinus pennsylvanica_
8. Twigs smooth.
11. Leaf scars oval; buds brownish-black to black
_Fraxinus nigra_
11. Leaf scars half-round; buds brown.
12. Leaf scars notched at the top
_Fraxinus americana_
12. Leaf scars more or less straight across the top
_Fraxinus pennsylvanica_ var. _subintegerrima_
5. Bundle scars usually 3-7 (sometimes 9 in _Acer negundo_).
13. Leaf scars very broad, usually at least ⅓ inch across.
14. Bark smooth _Aesculus discolor_
14. Bark becoming furrowed and scaly _Aesculus glabra_
13. Leaf scars narrow, less than ⅓ inch across.
15. Buds with 2 exposed outer scales.
16. Twigs gray or gray-brown.
17. Buds long and narrow, at least 5 times longer than
broad _Viburnum lentago_
17. Buds shorter, at most 3 times longer than broad.
18. Buds reddish-brown.
19. Buds smooth or scurfy _Viburnum prunifolium_
19. Buds hairy _Viburnum rufidulum_
18. Buds light brown.
20. Buds hairy _Cornus drummondii_
20. Buds smooth or nearly so _Cornus racemosa_
16. Twigs purple or orange-brown.
21. Twigs purplish _Cornus florida_
21. Twigs orange-brown, at least usually not purplish
_Cornus racemosa_
15. Buds with more than 2 exposed scales.
22. Twigs green or glaucous _Acer negundo_
22. Twigs brown.
23. Buds rounded, several in a cluster; twigs red or
orange.
24. Twigs hairy _Acer rubrum var. drummondii_
24. Twigs smooth.
25. Twigs with an unpleasant odor; bark scaly
_Acer saccharinum_
25. Twigs without an unpleasant odor; bark not
scaly _Acer rubrum_
23. Buds elongated; twigs brown or gray.
26. Ends of some twigs tapering to a spine
_Rhamnus cathartica_
26. Ends of twigs not spiny.
27. Twigs (at least by the time they are 2 years
old) pale gray-brown, dull _Acer nigrum_
27. Twigs pale reddish-brown, shiny.
28. Buds pointed at the tip _Acer saccharum_
28. Buds more or less rounded at the tip
_Acer barbatum_
3. Leaf scars alternate.
29. Thorns or spines present.
30. Spines in pairs _Robinia pseudoacacia_
30. Spines solitary, although sometimes branched.
31. Spines scattered all along the twigs and branches
_Aralia spinosa_
31. Spines not scattered all along the twigs and branches.
32. Thorns branched _Gleditsia spp._
32. Thorns unbranched.
33. Buds pointed at the tip.
34. Twigs usually hairy _Malus ioensis_
34. Twigs usually smooth.
35. Buds with reddish scales _Malus coronaria_
35. Buds with chestnut-brown scales
_Malus angustifolia_
33. Buds more or less rounded at the tip.
36. Terminal bud absent _Maclura pomifera_
36. Terminal bud present _Crataegus spp._
29. Thorns or spines absent.
37. Pith chambered, at least at the nodes.
38. Leaf scars 3-lobed and usually with 3 groups of bundle
scars.
39. Pith pale brown; leaf scars without velvety hairs at
the top _Juglans nigra_
39. Pith chocolate-brown; leaf scars with velvety hairs at
the top _Juglans cinerea_
38. Leaf scars half-round, not 3-lobed.
40. Pith chambered only at the nodes; stipular scars
present.
41. Buds about ¼ inch long _Celtis occidentalis_
41. Buds about ⅛ inch long.
42. Twigs usually smooth; trees _Celtis laevigata_
42. Twigs usually hairy; shrubs _Celtis tenuifolia_
40. Pith chambered between the nodes as well as at most of
the nodes; stipular scars absent.
43. Exposed bud scales 2 _Diospyros virginiana_
43. Exposed bud scales 4 _Halesia carolina_
37. Pith solid, although sometimes with diaphragms.
44. Pith with diaphragms.
45. Buds without bud scales _Asimina triloba_
45. Buds with 1 or more scales.
46. Bud scales 1-2; bundle scars 7 or more; stipular
scars present.
47. Bud scale 1, hairy _Magnolia acuminata_
47. Bud scales 2, smooth _Liriodendron tulipifera_
46. Bud scales 3-several; bundle scars 3; stipular scars
absent.
48. Buds about ¼ inch long _Nyssa sylvatica_
48. Buds up to 1 inch long _Nyssa aquatica_
44. Pith without diaphragms.
49. Bundle scar 1.
50. Twigs orange; bark reddish-brown _Larix decidua_
50. Twigs orange; bark reddish-brown _Larix laricina_
49. Bundle scars 2 or more.
51. Stipular scars forming a ring around the twig
_Platanus occidentalis_
51. Stipular scars not forming a ring around the twig,
or absent.
52. Twigs aromatic when cut.
53. Twigs green; buds generally smooth
_Sassafras albidum_
53. Twigs orange-brown; buds generally hairy
_Betula lutea_
52. Twigs not aromatic when cut.
54. Buds without scales.
55. Terminal buds larger than the rest of the
buds.
56. Buds rusty-hairy or gray-woolly.
57. Buds rusty-hairy, 2-3 times longer than
broad _Asimina triloba_
57. Buds gray-woolly, not much longer than
broad _Malus ioensis_
56. Buds smooth or, if hairy, not conspicuously
rusty-hairy or gray-woolly.
58. Leaf scars lobed; twigs without stipular
scars.
59. Buds bright yellow _Carya cordiformis_
59. Buds brown or reddish-brown.
60. Terminal bud up to ½ inch long; twigs
with orange lenticels
_Carya illinoensis_
60. Terminal bud up to ¼ inch long; twigs
with pale lenticels _Carya aquatica_
58. Leaf scars unlobed; twigs with stipular
scars.
61. Buds pale brown; twigs often zig-zag
_Hamamelis virginiana_
61. Buds light brown; twigs mostly straight
_Rhamnus caroliniana_
55. Terminal buds smaller than other buds, or
absent.
62. Pith reddish-brown; leaf scars often ½ inch
across _Gymnocladus dioicus_
62. Pith not reddish-brown; leaf scars less than
½ inch across.
63. Milky sap present.
64. Twigs hairy.
65. Twigs velvety; pith yellow
_Rhus typhina_
65. Twigs not velvety; pith whitish
_Rhus copallina_
64. Twigs smooth _Rhus glabra_
63. Milky sap absent.
66. Leaf scars completely encircling the bud
_Cladrastis lutea_
66. Leaf scars only partly encircling the
bud _Ptelea trifoliata_
54. Buds with 1 or more scales.
67. Buds with 1 scale _Salix spp._
67. Buds with 2 or more scales.
68. Bundle scar 1.
69. Twigs with short spur-like shoots
_Ilex decidua_
69. Twigs without short spur-like shoots
_Diospyros virginiana_
68. Bundle scars 2 or more.
70. Buds at least 4 times longer than broad.
71. Stipular scars encircling the twig, or
nearly so _Fagus grandifolia_
71. Stipular scars not encircling the twigs,
or absent.
72. Lowermost bud scale directly above the
leaf scar _Populus deltoides_
72. Lowermost bud scale to one side of
leaf scar.
73. Twigs reddish-brown, with pale
lenticels _Amelanchier arborea_
73. Twigs gray-brown, with dark
lenticels _Amelanchier laevis_
70. Buds less than 4 times longer than
broad. (Go to 74)
74. Pith star-shaped, or triangular, or variously lobed in
cross-section.
75. Lowermost bud scale directly above the leaf scar.
76. Twigs densely hairy; bark white _Populus alba_
76. Twigs smooth or sparsely hairy.
77. Visible bud scales more than 4.
78. Buds smooth, shiny, brown _Populus tremuloides_
78. Buds hairy, dull, gray _Populus grandidentata_
77. Visible bud scales 3-4.
79. Buds at least ½ inch long _Populus deltoides_
79. Buds less than ½ inch long _Populus heterophylla_
75. Lowermost bud scale to one side of leaf scar.
80. Buds clustered near the tip of the twig; bud scales in 5 rows.
81. Buds at least ¼ inch long.
82. Buds angular.
83. Buds smooth _Quercus shumardii_
83. Buds hairy, at least at tip.
84. Buds hairy all over.
85. Buds with rusty or brown hairs.
86. Buds with rusty hairs _Quercus marilandica_
86. Buds with brown hairs _Quercus michauxii_
85. Buds with gray hairs _Quercus velutina_
84. Buds hairy only at the tip.
87. Buds light red-brown _Quercus pagodaefolia_
87. Buds dark red-brown _Quercus coccinea_
82. Buds not angular.
88. Buds and twigs orange-brown _Quercus prinus_
88. Buds and twigs red, red-brown, dark brown, or
gray-brown.
89. Buds red or red-brown.
90. Buds light red to light red-brown _Quercus rubra_
90. Buds dark red to dark red-brown _Quercus falcata_
89. Buds dark brown _Quercus coccinea_
81. Buds less than ¼ inch long.
91. Buds pointed at the tip.
92. Buds and twigs brown to orange-brown
_Quercus muhlenbergii_
92. Buds and twigs red to red-brown to gray-brown.
93. Scales of buds hairy.
94. Twigs dark red-brown to gray; buds red-brown
_Quercus falcata_
94. Twigs light or dark brown; buds gray-brown
_Quercus imbricaria_
93. Scales of buds smooth or nearly so.
95. Buds dark red-brown _Quercus phellos_
95. Buds light red-brown _Quercus palustris_
91. Buds more or less rounded.
96. Twigs red-brown, shiny.
97. Buds not angular _Quercus alba_
97. Buds angular _Quercus ellipsoidalis_
96. Twigs gray to yellow-brown to purplish, dull.
98. Twigs and buds smooth or nearly so.
99. Twigs purplish, with a whitish coating
_Quercus bicolor_
99. Twigs gray to yellow-brown _Quercus lyrata_
98. Twigs and buds hairy.
100. Buds red-brown _Quercus stellata_
100. Buds gray to gray-brown _Quercus macrocarpa_
80. Buds not clustered near the tip of the twig; bud scales not in
5 rows.
101. Bundle scars in more than 3 groups; leaf scars lobed.
102. Visible bud scales 2.
103. Buds bright yellow _Carya cordiformis_
103. Bud scales brown or reddish-brown.
104. Terminal bud up to ½ inch long; twigs with orange
lenticels _Carya illinoensis_
104. Terminal bud up to ¼ inch long; twigs with pale
lenticels _Carya aquatica_
102. Visible bud scales more than 2.
105. Some or all the terminal buds ½ inch long or longer.
106. Outermost bud scales falling away early, revealing
pale inner scales; bark not peeling _Carya tomentosa_
106. Outermost bud scales persistent; bark peeling.
107. Twigs orange-brown, with orange lenticels
_Carya laciniosa_
107. Twigs dark brown or red-brown, with pale lenticels
_Carya ovata_
105. Terminal buds usually less than ½ inch long.
108. Buds rusty-hairy, with silvery or yellow scales
_Carya texana_
108. Buds smooth or only slightly hairy, without scales.
109. Bark smooth or furrowed, not scaly _Carya glabra_
109. Bark becoming scaly _Carya ovalis_
101. Bundle scars in 3 groups; leaf scars not lobed.
110. Buds up to ⅙ inch long; twigs bitter to the taste.
111. Pith triangular in cross-section _Alnus glutinosa_
111. Pith not triangular in cross section.
112. Buds very shiny _Prunus serotina_
112. Buds dull _Prunus virginiana_
110. Buds longer than ⅙ inch; twigs not bitter to the taste.
113. Twigs sometimes with corky wings; buds with 4 or more
exposed scales _Liquidambar styraciflua_
113. Twigs without corky wings; buds with 2-3 exposed scales
_Castanea dentata_
74. Pith round or nearly so in cross-section.
114. Terminal bud present.
115. Buds with 2-3 exposed scales _Cornus alternifolia_
115. Buds with 4 or more exposed scales.
116. Bud scales fleshy _Crataegus spp._.
116. Bud scales not fleshy _Prunus spp._
114. Terminal bud absent.
117. Leaf scars at least ½ inch across; bundle scars 9
_Ailanthus altissima_
117. Leaf scars smaller; bundle scars not 9.
118. Stipular scars absent.
119. Leaf scars bordered by hairs _Cercis canadensis_
119. Leaf scars not hairy _Gleditsia spp._
118. Stipular scars present.
120. Exposed bud scales 2.
121. Milky sap present _Broussonetia papyrifera_
121. Milky sap absent.
122. Twigs gray or brown _Tilia americana_
122. Twigs light red _Tilia heterophylla_
120. Exposed bud scales 3 or more.
123. Exposed bud scales 3-4; lenticels horizontal.
124. Twigs with taste of wintergreen _Betula lutea_
124. Twigs without taste of wintergreen.
125. Twigs and buds smooth; bark white
_Betula papyrifera_
125. Twigs and buds somewhat hairy; bark reddish
_Betula nigra_
123. Exposed bud scales more than 4; lenticels more or less
circular.
126. Bundle scars not in groups of 3; milky sap present.
127. Buds about ¼ inch long _Morus rubra_
127. Buds about ⅛ inch long _Morus alba_
126. Bundle scars in groups of 3; milky sap absent.
128. Exposed bud scales usually about 12
_Carpinus caroliniana_
128. Exposed bud scales usually about 6.
129. Leaf scars and bundle scars slightly elevated
_Ostrya virginiana_
129. Leaf scars and bundle scars depressed.
130. Buds less than ⅛ inch long _Ulmus pumila_
130. Buds at least ⅛ inch long.
131. Some of the twigs with corky wings.
132. Buds about ¼ inch long _Ulmus thomasii_
132. Buds about ⅛ inch long _Ulmus alata_
131. None of the twigs with corky wings.
133. Buds rusty-hairy, about ¼ inch long
_Ulmus rubra_
133. Buds light brown, smooth, about ⅛ inch long
_Ulmus americana_

Trees of Illinois

SOUTHERN SUGAR MAPLE
_Acer barbatum_ Michx.

Growth Form: Medium tree up to 60 feet tall; trunk diameter up to 2
feet; crown rounded.

Bark: Smooth and pale brown at first, becoming darker and furrowed when
old.

Twigs: Slender, brown, smooth or hairy, usually with pale lenticels;
leaf scars opposite, U-shaped, with 3-7 bundle traces.

Buds: Rounded, reddish-brown, hairy, up to ¼ inch long.

Leaves: Opposite, simple; blades up to 4 inches long, nearly as broad,
palmately 3- to 5-lobed, drooping on the sides, the edges sparsely
and coarsely toothed, green and smooth or a little hairy on the
upper surface, paler and much hairier on the lower surface;
leaf-stalks up to 3 inches long, very hairy. The leaves turn
yellow or orange in the autumn.

Flowers: Staminate and pistillate borne separately, but sometimes on the
same tree, in dense clusters, yellowish-green, appearing as the
leaves unfold.

Fruit: Borne in pairs, composed of a wing with a seed at the base,
greenish, up to 1 inch long.

Wood: Heavy, strong, coarse-grained, light brown.

Uses: Furniture, interior finishing, cabinets.

Habitat: Woodlands.

Range: Virginia across southern Illinois to southeastern Oklahoma, south
to Texas, east to Florida.

Distinguishing Features: The Southern Sugar Maple resembles the Black
Maple because of its drooping leaves, but differs by its smaller,
thicker leaves.

BOX ELDER
_Acer negundo_ L.

Other Name: Ash-leaved Maple.

Growth Form: Medium tree up to 60 feet tall; trunk diameter up to 4
feet; crown wide-spreading.

Bark: Light brown, ridged when young, becoming deeply furrowed with age.

Twigs: Smooth, green, glaucous, or rarely purplish, shiny, usually with
white lenticels; leaf scars opposite, U-shaped, with 5-9 bundle
traces.

Buds: Rounded, white-hairy, up to ⅛ inch long.

Leaves: Opposite, pinnately compound, with 3-7 leaflets; leaflets
elliptic to ovate, up to 4 inches long, about half as broad,
pointed at the tip, tapering or rounded at the sometimes
asymmetrical base, smooth or usually coarsely toothed along the
edges or even shallowly lobed, light green and smooth on the upper
surface, paler and smooth or hairy on the lower surface.

Flowers: Staminate and pistillate borne on separate trees, several in a
cluster, greenish-yellow, appearing as the leaves begin to unfold.

Fruit: Borne in pairs, in drooping clusters, composed of a curved wing
with a seed at the base, greenish-yellow, up to 2 inches long.

Wood: Light weight, soft, close-grained, white.

Uses: Paper pulp, interior finishing, furniture.

Habitat: Moist woods.

Range: Vermont across to Saskatchewan, south to Texas, east to Florida.

Distinguishing Features: The Box Elder most nearly resembles ashes, but
differs by its green or glaucous twigs and its paired fruits.

BLACK MAPLE
_Acer nigrum_ Michx.

Growth Form: Medium tree up to 65 feet tall; trunk diameter up to 2½
feet; crown broad, with several upright branches.

Bark: Dark brown to black, smooth when young, soon becoming furrowed and
scaly.

Twigs: Slender, brown, smooth, often with pale lenticels; leaf scars
opposite, U-shaped, with 3-7 bundle traces.

Buds: Pointed, dark brown, finely hairy, up to one-fourth inch long.

Leaves: Opposite, simple; blades up to 6 inches long and nearly as
broad, palmately 3- to 5-lobed, drooping on the sides, the edges
of the leaves sparsely and coarsely toothed, green and smooth on
the upper surface, yellow-green and smooth or hairy on the veins
on the lower surface; leafstalks up to 5 inches long, smooth or
hairy. The leaves turn yellow in the autumn.

Flowers: Staminate and pistillate borne separately, but sometimes on the
same tree, in dense clusters, yellowish, appearing as the leaves
unfold.

Fruit: Borne in pairs, composed of a wing with a seed at the base,
reddish-brown to greenish, up to 1 inch long.

Wood: Heavy, strong, coarse-grained, brown.

Uses: Furniture, cabinets.

Habitat: Rich woodlands.

Range: New Hampshire across to Minnesota and South Dakota, south to
Louisiana, east to Georgia.

Distinguishing Features: The Black Maple is distinguished from the Sugar
Maple by its drooping leaves. It differs from the Southern Sugar
Maple, which also has drooping leaves, by its larger, thinner
leaves.

RED MAPLE
_Acer rubrum_ L.

Growth Form: Medium tree up to 70 feet tall; trunk diameter up to 3
feet; crown oval or rounded.

Bark: Gray and smooth when young, becoming darker and scaly.

Twigs: Slender, mostly smooth, more or less reddish, usually with pale
lenticels; leaf scars opposite, U-shaped, with 3-7 bundle traces.

Buds: Rounded, reddish, usually hairy, up to ¼ inch long.

Leaves: Opposite, simple; blades up to 6 inches long, nearly as broad,
palmately 3- to 5-lobed, the edges of the leaves sharply toothed
to nearly toothless, pale green and smooth on the upper surface,
white or gray and either smooth or hairy on the lower surface;
leafstalks smooth or finely hairy, up to 4 inches long.

Flowers: Staminate and pistillate borne separately, but sometimes on the
same tree, in dense clusters, bright red or yellow, opening in
February and March before the leaves begin to unfold.

Fruit: Borne in pairs, composed of an erect wing with a seed at the
base, red or yellow, up to 1 inch long.

Wood: Heavy, close-grained, light brown.

Uses: Furniture, gun-stocks.

Habitat: Swamps, low woods, upland slopes, bluff tops.

Range: Newfoundland across to Ontario, south to eastern Texas, east to
Florida.

Distinguishing Features: The Red Maple is characterized by its white
lower leaf surfaces and its shallowly lobed leaves. The similar
Silver Maple has very deeply lobed leaves.

SWAMP RED MAPLE
_ rubrum_ L. var. _drummondii_ (H. & A.) Sarg.

Growth Form: Medium tree up to 40 feet tall; trunk diameter up to 1
foot; crown narrow.

Bark: Gray and smooth when young, becoming darker and scaly.

Twigs: Slender, white-hairy when young, usually becoming smooth or
nearly so, reddish; leaf scars opposite, U-shaped, with 3-7 bundle
traces.

Buds: Rounded, reddish, hairy, up to ¼ inch long.

Leaves: Opposite, simple; blades up to 6 inches long, nearly as broad,
palmately 3- to 5-lobed, the edges of the leaves toothed, green
and somewhat hairy on the upper surface, densely white-hairy on
the lower surface; leafstalks stout, densely hairy, up to 4 inches
long.

Flowers: Staminate and pistillate borne separately, but sometimes on the
same tree, in dense red clusters, opening before the leaves begin
to unfold.

Fruit: Borne in pairs, composed of an erect wing with a seed at the
base, bright red, over 1 inch long.

Wood: Heavy, coarse-grained, light brown.

Use: Furniture.

Habitat: Wooded swamps.

Range: New Jersey across to Missouri, south to Texas, east to Florida.

Distinguishing Features: The Swamp Red Maple is distinguished from the
Red Maple by the dense coat of white hairs on the undersurface of
the leaves and by the longer fruits.

SILVER MAPLE
_Acer saccharinum_ L.

Other Name: Soft Maple.

Growth Form: Medium to large tree up to 100 feet tall; trunk diameter up
to 5 feet; crown usually broadly rounded.

Bark: Gray or silvery, smooth at first, becoming loose and scaly or even
somewhat shaggy when old.

Twigs: Slender, reddish-brown, smooth, often curving upward; leaf scars
opposite, U-shaped, with 3-7 bundle traces.

Buds: More or less rounded, reddish-brown, smooth to finely hairy, up to
⅛ inch long.

Leaves: Opposite, simple; blades up to 8 inches long, nearly as broad,
deeply palmately 5-lobed, the edges of the leaves sharply toothed,
pale green and smooth on the upper surface, silvery-white and
usually smooth on the lower surface, except in the leaf axils;
leafstalks smooth, up to 5 inches long, often reddish.

Flowers: Staminate and pistillate borne separately, but sometimes on the
same tree, in dense clusters, greenish-yellow, opening in February
and March before the leaves begin to unfold.

Fruit: Borne in pairs, composed of a curved wing with a seed at the
base, green or yellow, up to 3 inches long.

Wood: Hard, close-grained, pale brown.

Uses: Furniture; sometimes grown as an ornamental, but the branchlets
are brittle.

Habitat: Wet soil.

Range: New Brunswick across to Minnesota and South Dakota, south to
Oklahoma, Texas, east to northern Florida.

Distinguishing Features: The deeply lobed leaves which are silvery-white
on the flower surface best distinguish this tree.

SUGAR MAPLE
_Acer saccharum_ Marsh.

Other Name: Hard Maple.

Growth Form: Medium to large tree up to 80 feet tall; trunk diameter up
to 3 feet; crown broadly rounded, with many branches.

Bark: Gray to dark brown to black, becoming furrowed and scaly.

Twigs: Slender, smooth, brown, often with pale lenticels; leaf scars
opposite, U-shaped, with 3-7 bundle traces.

Buds: Pointed, dark brown, smooth or a little hairy, shiny, up to ¼ inch
long.

Leaves: Opposite, simple; blades up to 5 inches long, nearly as broad or
a little broader, palmately 3- to 5-lobed, the edges of the leaves
sparsely and coarsely toothed, dark green and smooth on the upper
surface, green or paler on the lower surface and usually smooth,
or sometimes hairy on the veins; leafstalks up to 3 inches long,
smooth and sometimes hairy. The leaves turn brilliant shades of
yellow and orange in the autumn.