wpe5.jpg (2127 bytes)U.P. TREE  IDENTIFICATION  KEY
from Michigan State University Extension


Identifying deciduous, or broad-leaf bearing, trees using leaves isn't too hard and can be fun. However, leaves can vary in shape and size with a species or even on the same individual tree.   Knowing as many identification features as possible is always a good idea.   But that takes practice. Working these keys also takes practice.

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.

If you’re not sure how to use a tree identification key like this, click here. (read the instructions!).

1. Opposite branching.  (2) 
Alternate branching.  (12)
Compound leaves.  (3)
Simple leaves.  (6)
Leaflets 3-5, coarsely-toothed.   BOXELDER
3.  Leaflets 5-9,
shallow-toothed.  (4)
4.  Leaflets 9-11, stemless. BLACK ASH
4.  Leaflets 5-9, with stems.  (5)
5. Top of
leaf scar smile-shaped. WHITE ASH
5. Top of leaf scar straight.  GREEN ASH
Tree size.  (7)
Shrub size.  (9)
Leaf margin smoothSUGAR MAPLE
Leaf margin toothed.  (8)
8.  Leaves
double-toothed, green both sides.  RED MAPLE
8.  Leaves with deep
sinuses, silvery underneath.  SILVER MAPLE
9.  Leaf veins
palmate, maple-like.  (10)
9.  Leaf not palmate.
10.  Leaf
sinuses roundish, trunk with obvious stripes.  STRIPED MAPLE
10.  Leaf
sinuses sharp-angled, trunk gray.  MOUNTAIN MAPLE
11.  Leaves with
finely-toothed marginsBUCKTHORN
11.  Leaves with smooth
margins.    DOGWOOD         
Compound leaves.  (13)
Simple leaves.  (18)
13.  Leaflets over 2".  (14)
13.  Leaflets under 2".  (16)
14.  Leaflets 7-11, with largest at end of leaf.  Hickory nuts.  BITTERNUT HICKORY
14.  Leaflets 11-23, largest in the middle or all even length.  Twigs with
chambered pith.  (15)
15.  Leaves 15-30 inches long, 11-17 leaflets.  Dark pith.  BUTTERNUT
15.  Leaves 12-36 inches long, 15-23 leaflets.  Tan pith.  BLACK WALNUT
16.  Leaflets serrated  MOUNTAIN ASH
16.  Leaflets smooth margined.
17.  Leaves often
double-compound, many leaflet pairs.  HONEYLOCUST
17.  Leaves single-compound, 7-19 leaflets.  BLACK LOCUST

18.  Lobed leaves.  Smooth or toothed margins.  (19)
18.  Leaves not
lobedSimple leaves, toothed margins.  (22)
19.  Pointed lobes.  (20)
19.  Rounded lobes.  (21)
Sinuses usually no closer to mid-vein that 1/2 inch.  Tree usually with good form.  NORTHERN RED OAK
20.  Sinuses usually large and nearly to mid-vein.  Scrubby-looking tree.  NORTHERN PIN OAK
20.  Angled lobes or very large teeth. 
Toothed margins.  Thorns.  HAWTHORNE
21.  Leaf "club-shaped" with one pair of sinus that nearly to mid-vein.   Twigs with corky growths.  Acorn cups fuzzy.  Rare.  BUR OAK
21.  Lobes and sinuses fairly balanced.  Twigs without corky growths.   Acorn cups not fuzzy.  Rare.  WHITE OAK

22.  Papery bark, like birches.  (23)
22.  Bark not papery.  (24)
23.  Leaves
single-toothed, white peeling bark.   PAPER BIRCH
23.  Leaves
double-toothed, yellow or bronze bark.  YELLOW BIRCH
24.  Leaf stems flat.  (25)
24.  Leaf stems round.  (26)
25.  Leaves have small teeth (<1/16"), bark usually white.  QUAKING ASPEN
25.  Leaves have large teeth (1/8-1/4"), woolly underneath in the spring.  BIGTOOTH ASPEN
25.  Triangular leaf with base angled-back towards the twig.   Long, sticky buds.  COTTONWOOD
26.  Leaves & small twigs with bitter taste.  (27)
26.  Leaves & twigs not bitter.  (30)
27.  Rusty fuzz on back of leaf along mid-rib.  BLACK CHERRY
27.  No rusty fuzz.  (28)
28.  Leaf much longer than wide.  PIN CHERRY
28.  Leaf not much longer than wide.
Terminal buds long and slender.  JUNEBERRY
29.  Terminal buds shorter, only about 2-3 times the width of the twig.  CHOKE CHERRY
30.  Leaf margins
double-toothed, elm-like or birch-like leaves.  (31)
30.  Leaf margins not as above.  (35)
31.  Bark cross-section
layered and unequal leaf base.
31.  Bark not layered.
32.  Leaves 2-3 inches.  Bark and twigs with corky wings or ridges.  ROCK ELM
32.  Leaves usually over 3 inches long.  Bark not as above.
33.  Leaves 4-6 inches, very scratchy.   Inner bark slimy when chewed.  SLIPPERY ELM
33.  Leaves 4-6 inches.  Bark cross-section with alternate dark & light layers.  AMERICAN ELM
34.  Bark smooth, small
understory tree.  MUSCLEWOOD
34.  Bark shreddy, small
understory tree.  IRONWOOD
35.  Leaves much longer than wide.  (36)
35.  Leaves not so long & narrow.  (38)
Shrub size.  SMALL WILLOWS
Tree size.  (37)
Leaf bases rounded with stipulesBLACK WILLOW
Leaf bases sharply angled without stipules (or tiny ones).  PEACHLEAF WILLOW
Shrub or small tree.  Leaves may be somewhat lobed.  Thorns.  HAWTHORNE
Tree size.  (39)
39.  Heart-shaped leaves.  Trees often in clumps.  Brick-red, smooth buds.   BASSWOOD
39.  Leaves not heart-shaped.  (40)
40.  Leaves with large, coarse, pointed teeth.  AMERICAN BEECH
40.  Leaves with teeth that are not so obvious.  (41)
41.  Leaves are rusty-looking with barely serrate margins.  Long, sticky buds.  BALM-of-GILEAD
41.  Leaf serrations point to leaf tip.  Twigs and bark with corky ridges.  HACKBERRY

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

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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. 

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