Page 15 - Forest Trees of Maine

23. Twigs angular; pith star-shaped Oak p. 106-123
23. Twigs round, spicy odor and taste; leaves 0–3 lobed Sassafras p.165
24. Leaf margin singly toothed or serrated 25
24. Leaf margin doubly serrated 31
25. Teeth hooked, prominent; fruit a bur 26
25. Teeth not hooked, fruit not a bur 27
26. Pith star-shaped; buds blunt; bark brown American Chestnut p. 124
26. Pith round; buds long, pointed; bark gray American Beech p. 104
27. Leaf base one-sided, leaf cordate; pith not symmetrical American Basswood p. 134
27. Leaf base even; pith symmetric in cross section 28
28. Leaves long and narrow; petioles short without glands; buds with a single, cap-like scale Willows p. 68
28. Leaves broad, or if narrow with glands on petiole; buds with several scales 29
29. Leaf petiole usually long, flat, except rounded in balsam poplar; pith star-shaped Aspen/Poplar p. 61-67
29. Leaf petiole short, not flat; pith round 30
30. Twigs pungent when broken; glands on petiole Cherry, Plum p. 139-145
30. Twigs odorless; leaf petiole glandless; buds slender, twisted at tip, silky within Serviceberry p. 148
31. Leaf base one-sided, surface sand-papery Elm p. 136
31. Leaf base even, surface smooth 32
32. Branches with thorns 1 inch or more long Hawthorn p. 147
32. Branches without thorns 33
33. Pith triangular; buds stalked, smooth Speckled Alder p. 102
33. Pith not triangular; bud scales overlapping 34
34. Leaves hairy on both surfaces; pith green Eastern Hop-Hornbeam p. 98
34. Leaves if hairy only so on one surface; bark smooth 35
35. Stem fluted; bark smooth, gun-metal gray American Hornbeam p. 100
35. Stem not fluted; bark white, yellow, or red to dark brown Birch p. 87-96
36. Leaflets with margin entire 37
36. Leaflets with serrated margin 38
37. Twigs with paired spines; 7–19 leaflets Black Locust p. 162
37. Twigs spineless; 7–13 leaflets; leaflets poisonous Poison-Sumac** p. 6
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38. Leaflets ⁄2 inch long with fine, rounded teeth Honeylocust p. 164
38. Leaflets over 1 inch long 39
39. Pith chambered or diaphragmed Black Walnut/Butternut p. 155–157
39. Pith solid 40
40. 5–7 leaflets; pith star-shaped Shagbark/Bitternut Hickory p. 152–154
40. 11–31 leaflets 41
41. Twigs smooth; 11–17 leaflets; buds large Mountain Ash p. 150
41. Twigs densely hairy; 11–31 leaflets; buds small Staghorn Sumac p. 168

** See also Poison ivy, page 6

SUMME R KE Y 13