Common Ground 707 – Identifying Trees of Northern Minnesota

Lakeland Public Television
presents Common Ground brought to you by the Minnesota
Arts and Cultural Heritage Fund and the citizens of Minnesota. ♪ ♪ tool pounding ♪ ♪ high pitched clank, tractor
rumbling ♪ ♪ ♪ flute playing ♪ flute playing ♪ flute playing Welcome to Common Ground. I’m
your host Scott Knudson. In this episode retired biology teacher, Rob
Knudson, my dad, takes us into the woods to
teach us how to identify trees by their leaves. ♪ ♪ I’m Rob Knudson. I was an ecology teacher for 25
years and I always started out in the
fall with a forest management practices
unit. And the very first thing we always did was we learned
the names of the trees based on the shape of their
leaves and that’s what we’d like to do in
this program. We’re not going
to do the shrubs, we’re not going to do
the ten foot tall stuff, we’re not going to do the
brush. But when you go out in
the woods and look up at full size trees
in north central Minnesota, these are
the trees that you’re going to
see. It’s always more enjoyable to take a walk in the woods
when you can understand what it
is that you’re looking at. OK, this is a really common tree around here. You
might notice you probably recognize the shape from the
Canadian flag and you probably
recognize it is a maple tree. It’s not
the only maple tree we have here but this particular one has obviously the three main parts
of the leaf and a nice, smooth edge between the points. This is
sugar maple. OK, and this is one of the two
most common maple trees that we have
in northern Minnesota. The three major points, smaller
points on it. The thing that distinguishes
this particular maple which is
sugar maple, some people refer to it
as hard maple is that between the points,
it’s nice and smooth. The other kind of
maple that we have you’ll see has smaller
teeth between the main teeth. This is sugar
maple. and you can also identify older
sugar maples by their trunk. rooster crowing OK, and this is the trunk of a typical older
sugar maple tree. You’ll be able to
recognize these and again the
thing to do is once you recognize the leaf,
then look at the trunk and look at the
shape of the tree and try to
learn from that. Older sugar maple trees very
often times turn black. They almost look like they’ve
been on fire. And you can see on this one that the
trunk is black compared to most
trees. ♪ ♪ ♪ OK, and this, this is American basswood. And it’s
obviously very large leaves but the thing
you want to watch for with American basswood from other
leaves is it’s bigger on one
side than it is on the other side,
you can see that’s true of all
the leaves and it doesn’t have a pointed
tip. Larger on one side, smaller on the other side.
American basswood. ♪ ♪ ♪ OK, there are several species of ash in northern Minnesota. This is the most
common one and the only one we’re going to
do in this program. This is green ash and what I’d
like you to notice about this is the reality is
this is one leaf and these are called leaflets. And in the ash species, all of
the ash species there’s black ash, green ash,
white ash and in town you’ll find
mountain ash. The ones with the
orange berries. You’ll see that they always
have leaflets that come out directly across from each other
in a pattern like that. This is green ash. ♪ ♪ OK, this tree right here is one of the more obscure
trees in the woods but it’s a good one to know. If
you look at the leaves of this tree, they’re fairly concentric. They might be a little bit
bigger on side than the other
but the thing to note about this is
that they’re nice, neat saw- tooth, all the way around from
the bottom to the tip on both sides, just
a single sawtooth. This is hornbeam. A lot of times the common name,
the local name for this is ironwood but it’s
actually hornbeam, and this is about as
big as a typical hornbeam tree
would be. It’s usually really twisted and kinda gnarly
looking. But this is hornbeam. ♪ Here’s a tree that’s actually
quite identifiable by its leaf. It’s a real typical
looking leaf but if you look real close it
has sawteeth that are fairly big
and then in between those sawteeth there are very,
very tiny sawteeth. But the reality is, there’s no
use learning this leaf because it’s
from a tree that’s more obviously recognized by
its bark. This is paper birch. OK, this tree is one of the two most common
type of aspens what most people call
popples. This particular one, if you look at it, has teeth along the edge and a fairly good size leaf.
This is appropriately named big-toothed aspen and the
leaves are bigger than this which is trembling aspen which has smaller, smoothed edge, round
leaves. And here’s a real good look at some
trembling aspen. And we’ve got literally a four mile an hour
breeze going right now and you
can see that even a slight breeze causes those rounded leaves to
wiggle back and forth, to tremble if you will.
Probably has an adaptive value of keeping
off insects and insect larvae like
caterpillars. Again, note the nice, round,
smoothed edge leaves on trembling aspen.
Bigtooth aspen and trembling aspen. The
two most common types of poplar in northern Minnesota. ♪ ♪ Now this tree is red maple. You may remember that when we
looked at sugar maple, sugar
maple had the same shape of a leaf
but sugar maple had points that were nice and
smooth between the points. Difference between red maple
and sugar maple? Red maple has the points just
like sugar maple did but in between the
points it has smaller points like a little sawtooth. This is
red maple. Also known as soft maple. OK, this tree that’s behind me
right now is one of our most common
species of oaks around here. I would like you
to notice on this one, this leaf has real pointed tips. These trees are actually
members of the red oak group. Note this one. This is a common northern red oak and this is even more common
around here and it’s called a pin oak. You might notice
that the northern red oak and the pin oak both have real
pointed tips but the pin oak obviously has
very, very deep notches whereas the northern red oak
has shallow notches. This is pin oak and this is
northern red oak. OK, here’s another example of an oak tree. What you might notice that this
one’s totally different than
the last oaks we looked at. This oak, instead
of having pointed tip leaves has a round tip
leaves. Now a lot of people call these
white oaks but in reality these are bur
oak. White oaks traditionally live a
few hundred miles south of here. We have a
few around, you’re likely to find them planted in
people’s yards and on old farmsteads but the real common
oak that we have around here with rounded tips
is bur oak and you can tell bur oak from white
oak. Bur oak has notches at the bottom and then
the outer part of the leaf the notches are not nearly as
deep and they’re rounded on the
edges. This is bur oak. If this were a
white oak these deep notches would go all
the way to the end of the leaf. There’d be like three more
notches in here. This is bur oak. ♪ These trees in the background
right here are American basswood and we identify that
by this huge leaf with an asymmetric shape where
it’s bigger one side than the
other. This was basswood. We have
another real common tree around here that’s asymmetric, you can see that
right here. This is American elm. And
American elm, one side is bigger than
the other. It isn’t nearly as big as the basswood
and it has real nice looking teeth along the
edge and on the teeth there are
smaller teeth. This is American elm. Now in town, you may see leaves
that look like these only they’re much
smaller, those are probably
Chinese elm and somebody probably planted
them but these trees in the woods usually have
leaves about this big, maybe
even bigger and they’re American elm.
Bigger on one side than the other, not nearly as
big as basswood. With nice defined teeth with
teeth on the teeth. Be aware that in some of
the species of trees that we’re going to be
looking at, there’s a lot of
natural genetic variation. The leaves
won’t all look exactly like the ones
we’re looking at just like a
deer. One deer is not exactly the
same color as another deer or doesn’t have exactly the
same shape of antler. Not every leaf will be shaped
exactly like the ones we’re
looking at. But they’re going to be close.
We’re going to start with the
maples. The maples are a good one to
start with because they have a shape that’s a good
foundation for comparison of the other
types of trees. And if you go out into the
woods you’re going to find two
kinds. You’re going to find sugar maple and you’re going to find red
maple. Uh, you might notice that they
have the same basic shape. The maple leaf
would be a good one to memorize what it looks like but you’ll
notice that the sugar maple has a nice, smooth
edge to it whereas the red maple has a serrated edge to it. Same
shape leaf same basic kind of tree but smooth edge and serrated edge. Now in town there are two other maples.
This one here is one of the most common yard
trees that we have in northern
Minnesota. This is silver maple. You might notice its got
the same maple leaf shape. It doesn’t have the
serrated edges like red maple. It has more of a
smooth edge but you might notice that these notches are much
deeper than in a sugar maple. This is silver maple. Sugar maple, red maple. And
this one right here doesn’t look like a
maple but in fact it is, it’s in the same genius. OK, this is
boxelder. Another one that you’re going to find real
common in town but very seldom out in the woods. This
is actually one leaf we’re looking at, it’s called a
compound leaf. This is the main
part of the leaf and these are
leaflets. This is boxelder. And boxelder can be recognized
because it has basically a three pointed
tip to it usually and then a couple of other subsidiary
leaflets. Boxelder, silver maple, common
in town not in the woods. Real common
in the woods around here, sugar maple,
maple shaped leaf, smooth edge, red maple,
same shape serrated edge. These are the
two common trees in the woods. In town silver maple looks kinda like sugar
maple. Fairly smooth, it has teeth but fairly
smooth edge but very, very deep notches. And boxelder which is one leaf, these are
leaflets. Boxelder has a triple pointed leaf with
some smaller leaves up the shaft. Lets take a look
at the oaks. When you’re walking
through the woods in northern Minnesota, you’re highly likely
to find these three. This one and this one are very
common. This one’s pretty common. These
first two you might notice have pointed tips where these here have rounded
tips. Now very, very common in northern Minnesota
are these two right here. This one with the real pointed
tips with very, very deep notches, is pin oak. Right next to it with pointed
tips but shallower notches, this is red oak. Northern red oak, pin
oak. Real common, both trees around
here. This one, most people in northern Minnesota refer to
this as white oak but in reality it’s bur oak and
bur oak has instead of pointed tips it
has rounded tips to the leaves. And it has
notches at the base of the leaf but the
terminal portion of the leaf is usually pretty
much one big palmated piece. OK, this is
bur oak. We do have some white oak around and the way you’ll recognize a
white oak tree is if all of the leaves on the
tree have deep notches with rounded tips and
the notches go all the way out the end. This is
not a very good example of
white oak. In fact in reality this is probably bur
oak but it shows what you need to look
for. White oak has notches that go all the way in,
all the way up to the tip even more so than this one with
rounded tips. White oak, rare around here,
real common farther south. Very common around here,
bur oak commonly called white oak.
Rounded portion palmated end with the notches
at the base of the leaf and then the two pointed leaf
ones, northern red oak and pin oak. OK, these are the aspens. Most people
call them popples. Technically they’re aspens.
There are actually two that are real common in the
woods that most people really don’t realize there’s a
difference. The trunks look exactly the same. Or pretty
much exactly the same. To look at the trunks you
probably wouldn’t be able to
tell a difference but if you look at the leaves
they are in fact different. These have a bigger leaf than
these. These have teeth around the edge and these
have small teeth but not like this one. OK, this
right here this is trembling aspen.
Sometimes called quaking aspen.
Especially out west they refer
to these as quakies or quaking aspen. These
are the ones that have the rounded leaf and when
the wind blows they shake. That’s why they’re
called trembling aspen. nature sounds nature sounds This, for obvious reasons is
called bigtooth aspen. Bigtooth aspen
and trembling aspen are very common. These
two right here are trees that you’ll find in
town, once in a while out in the woods,
once in a while you’ll find one
of these, these are more common a little
bit west of here out in more of where it starts
turning into prairie country but they are in town. This is a
cottonwood but it’s also a type of aspen.
One of the fastest growing
trees there is. And cottonwood you can see has
smaller teeth and a pointer tip than either
of the aspens, smaller teeth than the bigtooth
aspen. This one we really don’t even need to
have a leaf because the tree is more recognizable from its
trunk. This is Lombardy poplar and you
really don’t need to learn the
leaf on this one because you’ll
recognize this one from the
shape of the tree. The tree is totally straight up
and down with the side branches clinging to the side
of the tree. There the real
tall, straight ones that you see in
people’s yards. nature sounds The cottonwood and Lombardy
look similar except for obviously the leaf is wider
than it is long. Cottonwood, more toward out in
the prairie. Lombardy poplar, more of a yard
tree. I’ve never seen one in
the woods. Cottonwood, Lombardy poplar, not out in the woods, you won’t
find them almost never. These are the two from
the woods bigtooth aspen with big teeth
and trembling aspen are the ones you’ll find
very commonly around here. These two are examples of ash trees. We
actually have several types of ash around
here but I think for the purpose of what we’re
doing here, lets just learn
this is ash. But they all have one thing in
common. They all have a large leaf divided into
leaflets, a compound leaf again like
we’ve already seen. On ash trees all the time the leaflets are directly
across from each other and that’s how you recognize an
ash. This particular one is
green ash and this is very, very
common in the woods. We have green ash like this. We also have black ash and
white ash which are a little bit narrower
leaves than these but they
still have leaves that are directly across
from one another. This one right here, you’ll see
mostly in town and this is mountain ash. This is the tree that grows
those beautiful orange berries
that the cedar waxwings love so well
in the fall. And once in a while I have actually seen
these out in the woods but uh, usually it’s because
the birds eat the berries and
carry the berries and deposit them in the
woods and they grow. But you
will notice that mountain ash, just
like the green ash has a leaf that’s divided into
leaflets and the leaflets are directly across from one
another. This one could be confused with a leaf
like this which looks kind of
similar but I’d like you to notice that these leaves come
out alternately. One comes out on
this side, then one on this side and then one on
that side instead of being straight across from
one another like they were on
the ash, they’re out to the side. And
this is one of several different kinds
of willows that we have around here. And all of
the willows that we have and
I’m not even going to get into the
willows. All of the willows
will have kind of long, narrow leaves
that are alternating the way
they come off of the stem. Also, the willows this is one leaf, where this is
one leaf of an ash. As the ash trees all have them directly across
from one another. The willows all have them
alternating. We have green ash, white ash and black ash in northern
Minnesota. But for this program lets just
worry about them being called
ash. This is green ash. nature sounds nature sounds OK, here are some trees that
are a little bit harder to define then some of the ones
we’ve looked at. But they’re all very, very
common here but there are some
things about them that make them easy to
figure out. OK, this one right here and
this one right here, you might notice
that they’re asymmetrical. They’re bigger on one side then
they are on the other side. OK, these
two are pretty uniform from side to
side. Uh, this one has very defined
big sawteeth with sawteeth on the sawteeth whereas this one has just a
simple sawtooth pattern. This one is rounder than this
one. Uh, this one, if you compare it
to this one are kinda the same but again this one’s
symmetric, this one is not. OK, what these
are and I’ll get back to this, this
is basswood. One of the biggest leaves you’ll find in
the woods. It’s the biggest leaf you’ll find on a full size tree
in the woods for sure. This is American elm. Another real
common tree in the woods. Those are the two trees that
have the not equal on either side shape. This leaf right here looks
kinds of like elm and it’s kinda…again a
generic looking leaf. It has smaller teeth than
elm but the main thing is it’s not bigger on one side
than the other side. Uh, common name for this one
around here is ironwood but the fact is it’s
actually hornbeam. Uh, this is one that we talked about earlier
that you can recognize by that twisted, gnarly trunk. And they
don’t get very, very big. You’ll never find a 50
foot tall hornbeam tree they’re more like 25 feet tall.
And this leaf is quite definable if we
wanted to get into it but this is the one that was so
obviously recognizable by the bark that we don’t need to learn the leaf.
This is paper birch and it’s
very easily recognized from the bark rather
than the leaves. The bark was that tree that it was
peeling off and it looked like
paper. White birch or paper birch,
real common. Identify paper birch from the
bark. Hornbeam and birch are probably
more recognizable from their shape of the trunk
and the bark than they are from the shape of
the leaf. But hornbeam has little tiny teeth compared to
elm. Elm is bigger on one side than
the other and hornbeam is not. Basswood is a
big rounded leaf with kind of a
single sawtooth. Basswood, American elm, hornbeam and don’t worry about the leaf,
it’s birch. OK, lets take a little quiz on
this and see how you do. OK, here
that real definable shape we talked about. Smooth
along the edges as opposed to this one. Notches
not as deep as this one. This one, this one
and this one all have pretty much the same shape.
Smooth edges, jagged edges, deep notches, found in town. Same family, compound leaf, three tips, found in town. ♪ Sugar maple, hard maple. ♪ Red maple, real common in the
woods. ♪ OK, silver maple, not very
common in the woods but really
common in town. Boxelder. Actually a maple, one of the
most common shade trees in the city. Common in the woods, both of
them, pointed tips, shallow notches, deep notches. This one, rounded edges, notches at the base of the leaf but not at the
end of the leaf. ♪ Northern red oak. ♪ Pin oak. ♪ ♪ Bur oak. These two, the two most common ones found
around here, one of them has much rougher edge. This one
is the small, round leaf that blows in the wind,
this is the one that normally
happens a little farther to the west in
the prairie. Great, big tree. Nice to find teeth along the
edges. This is the one that has the
real straight trunk with the branches that
come straight up the side. ♪ ♪ Trembling aspen. ♪ Bigtooth aspen. ♪ Eastern cottonwood. ♪ Lombardy poplar found in town. Here’s the two that have one side bigger than
the other side. This is the big, rounded leaf
one. Little pointier leaf with
double sawteeth along the edge. This was the one that had the twisted trunk with smaller teeth and it’s the
same on both sides as opposed
to that one. This one is the one you
recognize from white bark. Here’s the one where the
leaflets come out directly opposite each
other. And here’s a smaller version of the same kind of
leaf, the one’s that have
berries that you find in your yard. American elm. ♪ Basswood. ♪ Hornbeam. Again, commonly called ironwood. ♪ White birch or paper birch.
Don’t worry about the leaf remember the trunk. ♪ Green ash. ♪ Mountain ash. Usually found in
town. It’s always more enjoyable to
walk through the woods when you can recognize what you’re
looking at. I hope what we’ve
done today will make your woodland
walk a little bit more enjoyable. ♪ ♪ ♪ ♪ Thanks for watching. Join us again on Common Ground. If you have an idea for a
Common Ground piece that pertains to north central
Minnesota email us at [email protected] or call us at 218-333-3014 218-333-3014. To view any
episode of Common Ground online, visit
us at ♪ ♪ ♪ ♪ To order episodes or segments of Common Ground, call
218-333-3020 218-333-3020. Common Ground is brought to you
by the Minnesota Arts and Cultural Heritage Fund
with money from the vote of the people,
November 4, 2008.


  1. If my “box elder “ has only three leaflets per leaf. Am I miss Identifying it? Or is it another sp.?

  2. Explained in detail and with clarity. My salute to you "Sir Knudson". Bravo. Made my walks more interesting and productive.

  3. Thank you. I like the videos where the person focuses on the LEAVES. Ones where people focus on the bark and the canopy are hard for me because all I can take home with me is the LEAF. Canopy shots of trees don't allow much differentiation. So thanx for focus on the LEAVES.

  4. Excellent explanations , incredible knowledge , really benefit from this video , words of wisdom right there !

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