Page 11 - Forest Trees of Maine
P. 11
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This book contains keys to help you identify trees in both winter and summer.
These are dichotomous keys; they work by giving you pairs of choices called couplets.
Each couplet has the same number located on the left side of the key.
Begin at couplet number 1. Read both choices carefully to determine which
matches the tree you are trying to identify. After you make your choice, the num-
ber at the right tells you which couplet to go to next. Go to that couplet and decide
which choice matches your tree; repeat the process until you arrive at a name or
species group for your tree.Turn to the page indicated and compare your tree to the
species in the table to figure out the individual species.
The final step is to compare your tree to the pictures and drawings in the
book. If they don’t seem to match your specimen, don’t be discouraged; return to
the key and check to see if you made an error. Remember that leaves and bark can
vary a lot even on the same tree, but the photograph can only show one example.
To help you with the terms in the key, a glossary is provided on page 14.
Example: We want to identify the tree these needles came
from. Starting at the first couplet, choose the descriptions that
fit the specimen. The lines in red indicate the correct choices
in the key.
SEE GLOSSARY PAGE 14 GO TO
1. Leaves are needle-, awl- or scale-like; conifers 2
1. Leaves are broad and veined, not as above; hardwoods or broad-leaf trees 9
2. Leaves needle-like 3
2. Leaves awl- or scale-like, or both 7
3. Leaves flat, tips blunt, and occur singly 4
3. Leaves angular in cross section, tips pointed 5
4. Leaves taper, twigs limber; cones shorter than 1 inch Eastern Hemlock p. 48
4. Leaves parallel-sided, twigs stiff; cones over 2 inches Balsam Fir p. 46
5. Leaves occur singly, never clustered Spruce p. 37
5. Leaves occur in clusters, also singly in larch 6
6. Leaves in clusters of 2–5 with papery sheath at base 1 Pine p.25
6. Leaves in clusters of 8 or more on spurs; papery sheath lacking Tamarack p. 50
2
We now know the tree is a pine. We then go to the species table to figure out what species of pine it is.
The tree is Eastern white pine.
HO W T O USE THE K E YS T O IDE NT IFY TR E E S 9
