Part 4

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.