DECIDUOUS WINTER  KEY

Be careful to READ THE DESCRIPTIONS CLOSELY and CAREFULLY!  Carefully compare the descriptions with your sample and your memory of what the tree and habitat looked like. Remember that words such as "often" and "usually" do NOT mean "always".  It is best to use a mature tree, or one that is not a seedling or sapling. Deciding if a small tree is just a shrub or if it is a young tree can be difficult. The appearance of a tree sometimes changes quite a bit as a tree ages (kind of like people). If you click on underlined, blue words, you will link to the glossary for a definition of that word. Underlined blue and CAPITALIZED words are names of trees that will link you to another page with several similar species.

1. Opposite branching. (2)
1. Alternate branching. (10)
  2.  Twigs often stout but never reddish. Dark terminal buds, sometimes large. Leaf scars are large. Ashes. (3)
  2. "Normal" or slender twigs. Maples & shrubs. (4)
3. Chocolate brown terminal bud. First set of side buds close to the terminal. Leaf scar has a distinct notch in the top. Bark is tight, furrowed in larger trees. WHITE ASH
3. First set of side buds usually set back 1/8 to 1/4 inch from terminal bud.  Leaf scar slightly notched. Bark flakes off easily when rubbed. Swampy habitat. BLACK ASH
3. Side buds tight against the terminal bud. Leaf scar top straight across. Twig ends tend to be somewhat flattened. Branching looks somewhat droopy. Bark often has many horizontal cracks. GREEN ASH
  4. Tree size, at least 4" diameter & 30 feet tall.  (5)
  4. Shrub size.  (8)
5. Youngest twigs reddish or purplish.  (6)
5. Youngest twigs gray or brownish.  (7)
  6. Terminal buds blunt and rounded. Twigs often with a gray or bluish powder. Bark medium brown and tight. Tree   often with poor form. BOXELDER
  6. Terminal buds reddish and blunt. Female flower buds, if present, occur in clusters. Bark is smooth and gray on young trees, becoming flaky or shaggy on large trees. RED MAPLE
7. Terminal buds blunt and rather brownish.  Twigs smell somewhat bad when crushed. Bark smooth and gray on young trees, becoming loose and peeling upward. Usually along river corridors or planted as an ornamental. Rare. SILVER MAPLE
7. Terminal buds quite sharp and pointy. Slender twigs, gray or medium-brown. Bark smooth and gray on young trees, becoming textured, thick, deeply fissured but always tight on large trees. SUGAR MAPLE
  8. Bark light colored, brown or yellowish or bark is red-purple. VIBURNUMS, DOGWOODS & OTHERS
  8. Bark medium to dark gray or greenish, may be striped.  (9)
9. Bark greenish with heavy white stripes. Buds much longer than wide, blunt. STRIPED MAPLE
9. Bark gray and smooth. Bud length about twice the twig width. MOUNTAIN MAPLE
9. Bark gray and smooth. Twigs end in spines.  BUCKTHORN
  10. Twigs with thorns or spines.  (11)
  10. Twigs without thorns.   (14)
11. Tree.  (12)
11. Shrub.  (13)
  12. Thorns under 1/4 inch and located in the crotches of twigs and branches. Rare. BLACK LOCUST
  12. Thorns longer. Twigs with a distinct "zig-zag" appearance. An ornamental. Rare. HONEYLOCUST
13. Thorns dark purple and at least 2 inches long. HAWTHORNE
13. Twigs that end in sharp points/spines.  Stems medium gray.  BUCKTHORN
  14. Terminal buds in clusters.  (15)
  14. Terminal buds single or absent.  (18)
15. Very stiff, smooth twigs. Medium to dark gray. Bark dark.  (16)
15. Twigs normal stiffness, light to medium gray. Bark medium gray.  (17)
  16. Bark smooth and gray on young trees, fissured with flattened ridges on older trees. Usually a reasonably well-formed trunk. NORTHERN RED OAK
  16. Similar bark but without flattened ridges on older trees. Inner bark yellowish. Usually a scrubby-looking tree growing on sandy sites. NORTHERN PIN OAK
17. Twigs with corky or warty ridges. Bark thick, even on young trees. Acorns with a fuzzy cup. Rare. BUR OAK
17. Twigs without growths and often greenish-maroon-brown. Acorn cups without fuzz. Rare. WHITE OAK
17. Twigs slender and bitter.  Usually a shrub.  PIN CHERRY
  18. Bark papery or mostly smooth (especially higher up in large trees).  (19)
  18. Bark mostly rough/textured/shreddy/etc.  (32)
19. Bark papery.  (20)
19. Bark mostly smooth, especially higher up in large trees.  (21)
  20. Papery bark white.  Smallest twigs purplish or dark brown. PAPER BIRCH
  20. Papery bark yellow or bronze.  Smallest twigs gray. YELLOW BIRCH
21. Tree size (over 20 feet or so).  (22)
21. Shrub or small tree size (under 20 feet or so).  (27)
  22. Bark color medium gray to dark gray.  (23)
  22. Bark color mostly white, light-gray, or olive-gray.  (24)
23. Bark black & scaly, like burnt potato chips. Buds sharp-tipped. BLACK CHERRY
23. Buds much longer than wide, cigar-shaped, brown.  Smooth bark even on large trees.  BEECH
  24. Red or maroon buds that are roundish and shiny. BASSWOOD
  24. Buds quite gummy when squeezed, usually over 1/2 inch long.  (25)
  24. Buds not gummy, under 1/2 inch.  (26)
25. Buds very gummy, reddish brown. BALM-of-GILEAD
25. Buds somewhat gummy, yellowish brown. COTTONWOOD
  26. Bark bright white to light-gray, sometimes slightly greenish. Buds shiny and 1/8 inch long. Side buds hug twig close. Very common tree. QUAKING ASPEN
  26. Bark can be light-gray sometimes with an olive-green cast. Buds dull, usually between 1/8 and 1/4 inch long. Side buds slightly point away from twig. Common, but less common than quaking aspen. BIGTOOTH ASPEN
27. Twigs not bitter. (28)
27. Bitter twigs.  (30)
  28. Terminal buds absent or "false" terminals cocked at a sharp angle.  SHRUB WILLOWS
  28. Terminal buds present.  (29)
29. Trunk sinewy, like muscles. Uncommon.  MUSCLEWOOD
29. Bark gray & cherry-like. Terminal buds hairy, about 3/8 inch long. Orange berries might be leftover from the Fall.  MOUNTAIN ASH
29. Terminal buds brick red, smooth, and about 1/8 inch long.  Trees often grow in clumps.  (45)
  30. Lower trunk bark black & scaly like burnt potato chips or showing cracks. Small buds sharp. BLACK CHERRY
  30. Bark mostly smooth.   (31)
31. Bark smooth and gray with wide lenticles across stem. Terminal bud length 1-2 times width. SHRUB CHERRIES
31. Bark smooth and gray. Terminal bud length more than 4 times width. JUNEBERRY
  32. Bark cross-section noticeably layered (break off a thick piece).  (33)
  32. Bark cross-section not noticeably layered.  (35)
33. Bark layers the same color. Inner bark slimy when chewed. Buds dark, almost black. SLIPPERY ELM
33. Bark layers red & white (or light & dark).  (34)
  34. Large trees with vase-like form.  Terminal bud distinctly cocked to one side and pointed. AMERICAN ELM
  34. Older twigs with corky growths. Buds very sharp-pointed. Rare. ROCK ELM
35. Older twigs have bark ridges on them. Rare. HACKBERRY
35. Twigs do not have bark ridges.  (36)
  36. Dark bark is scaly and looks like "burnt potato chips".  (37)
  36. Bark doesn’t look like above.  (38)
37. Twigs gray with sharp-tipped terminal buds.   BLACK CHERRY
37. Twigs with overlapped scales. Look for small cones.  A conifer without needles. TAMARACK
  38. Twigs very stout.  (39)
  38. Twigs normal size or slender, but not stout.  (41)
39. Yellow terminal bud. Pith not chambered.  BITTERNUT HICKORY
39. Leafy–looking terminal bud. Chambered pith. (40)
  40. Chambered pith chocolate-brown. Uncommon.  BUTTERNUT
  40. Chambered pith light brown. Rare.  BLACK WALNUT
41. Smaller understory tree, shreddy bark.  IRONWOOD
41. Shrub or tree.  Bark textured on trees & larger shrubs.  (42)
  42. Willow-like. No terminal buds or "false" terminal buds cocked at a sharp angle. Side buds without scales and pressed to the twig.  (43)
  42. Not willow-like.   (45)
43. Shrub size.  SMALL WILLOWS
43. Tree size. Yellowish twigs. Can grow to very large diameters.  (44)
  44. Common in ditches and along roads.  Fissured bark.  Yellow colored twigs, droopy, rather brittle.  BLACK WILLOW
  44. Uncommon. Twigs as above but flexible.  Small tree or large shrub.  PEACHLEAF WILLOW
45. Buds rounded & red or quite sticky.  (46)
45. Buds brownish. Bark in upper tree smooth and either white or light gray.  (47)
  46. Buds round and red, about 1/8 inch in size.  Bark medium-dark gray.  BASSWOOD
  46. Buds quite sticky and much longer than wide.  (48)
47. Bark bright white to light-gray, sometimes slightly greenish. Buds shiny and 1/8 inch long. Side buds hug twig close. Very common tree.  QUAKING ASPEN
47. Bark can be light-gray sometimes with an olive-green cast. Buds dull, usually between 1/8 and 1/4 inch long. Side buds slightly point away from twig. Common, but less common than quaking aspen. BIGTOOTH ASPEN
  48. Buds very gummy, reddish brown.  Bark cracked up & down (smooth on small trees).  BALM-of-GILEAD
  48. Buds somewhat gummy, yellowish brown.  Bark fissured.  COTTONWOOD

Some species not covered in this key but included in the species description pages are:  pears, plums, black maple, Norway maple, elderberries, weeping willow, pussy willow, and Bebb's willow. 

Click HERE to return to the home page.
A note to teachers about this site, click here.
Return to Michigan Society of American Foresters home page.
Return to the MSU U.P. Forestry home page.

This site created and maintained by Bill Cook, MSU Extension Forester for the Upper Peninsula of Michigan.   Editing and modification is ongoing.  Submit suggestions, questions, and corrections to cookwi@msu.edu or call 906-786-1575. 

MSU is an affirmative-action, equal-opportunity employer. Michigan State University Extension programs and materials are open to all without regard to race, color, national origin, gender, gender identity, religion, age, height, weight, disability, political beliefs, sexual orientation, marital status, family status or veteran status.