j. Four apple twigs.
4.. A children" s garden. For the pupils.
5. Some tent-makers.
6. What is nature-study f
7. Hints on making collections of insects.
8. The leaves and acorns of our common oaks.
9. The life- history of the toad,
to. The birds and I.
TI. Life in an aquarium.
T2. How the trees look in winter.
Bulletin 159 gives a general review of the Cornell Agricultural
Extension Work.
These will be sent free to all engaged in teaching in the public
schools of the State of New York.
Address,
Bureau of Nature- Study,
College of Agriculture,
Ithaca, N. K
TEACHER'S LEAFLETS
FOR USE IN THE PUBLIC SCHOOLS
PREPARED BY
NO. 13,
FEBRUARY, 1899.
THE COLLEGE OF AGRICULTURE,
CORNEL UNIVERSITY,
Issued under Chapter 67
of the Laws of 1898.
ITHACA, N. Y.
I. P. ROBERTS, DIRECTOR.
Evergreens, and How They Shed
Their Leaves,
BY H. P. GOULD.
ONE-BEARING evergreens are familiar to
everyone ; yet this familiarity is usually
with the trees as entire objects. We da
not often stop to analyze a tree in order to
find out what gives it its characteristic
appearance or to see what makes it look
as it does.
We will often find, if we stop to look,
that much of the character of a tree, that
is, its general appearance or the way in which it impresses us, is
due to the leaves and to their arrangement on the branches.
This is true of many of the evergreen trees.
Note to the teacher. This leaflet has two particular objects : to teach how
evergreens shed their leaves, and to enable you to distinguish a few of the
evergreens which are most commonly met. These studies (and those sug-
gested in Leaflet No. 12) should be the means of adding much cheer to the
winter. Encourage pupils to make collections of cones, to observe when
they shed their seeds,and how long ( how many seasons) they remain attached
to the branch. Remember that mere identification of the kinds of trees is
not the highest type of nature-study.
Cones are good subjects for free-hand drawing. Beginners should draw
them in outline, omitting the shading. Encourage pupils to draw* single leaf-
clusters of the different pines, cautioning them to get the right number of
leaves in each case.
148
Why are certain kinds of trees called evergreen, in distinction
from those which are said to be deciduous? The reason is
obvious. One kind is always green from the presence of foliage,
while the other sheds all of its leaves every season. The ever-
green trees, like the pines and the spruces and firs, always appear
to be well covered with foliage, so it does not often occur to us
that these trees shed their leaves. And yet perhaps we can
recall happy hours when we used to play beneath some large pine
tree where the ground was carpeted with pine ' ' needles. ' '
The falling of the leaves of the maple trees or the oaks is a
38. Shoot of the common white pine, one-third natural size.
familiar sight, but who has seen the spruce leaves fall, and who
can tell when the pine needles drop ?
That the evergreen trees do shed their foliage, as truly as the
maples and the elms do, we will not question, for we can see the
fallen leaves under any tree. Look up into the top of a spruce
or pine. See that the interior is bare of foliage. The leaves are
towards the ends of the branches, where they receive sunlight.
Yet the branches which are now on the interior once bore leaves,
for we can see the leaf-scars.
It will be interesting to find out something about the leaves of
our common evergreens. Let us look at some of them.
149
THE WHITE PINE.
In Fig. 38 is shown a white pine branch. Notice that the
leaves are borne in bunches or clusters of five. Each bunch of
leaves is produced in the axil (or angle) of a minute scale-like
body, but this scale cannot usually be found except on the very
young growth. It has been worn away or
broken from the older growth by the wind
and the rain and the other forces of nature.
Another strange fact should attract our
attention. The leaves of the maples and
other deciduous trees are borne only on the
present season's growth; but this is not
the case in the pines, and kindred trees.
If we trace back the growth of the past
two or three years, we shall find that there
are as many leaves on the wood that is two
years old as there are on the last season's
growth ; and in many cases we can find
leaves on the part of the branch that is
three years old. This means that the pine
leaves or needles are two and sometimes
three years old when they fall. The Fig.
38 shows the falling of the leaves from the
different years' growth. The part of the
branch between the tip and A is the last
season's growth ; between A and B it is two
years old ; the part between B and C is
three years old. The part that grew four
seasons ago beyond C has no leaves.
The different season's growth is not indicated by distinct
"rings" as in the case of deciduous trees (See Leaflet No. 3),
but by the branching. Each whorl of branches about a limb
represents the end of a season's growth. A young pine tree, or
the younger limbs of an old tree, show this character very plainly.
Do the leaves of the pines and of the other evergreen trees fall
at the end of the growing season, as the leaves of most of the
deciduous trees do? Or do they gradually become lifeless and fall
at any season, from the force of the wind and other forces of
39-
Cone of white pine. It
has shed its seeds. Half
natural size.
150
nature ? Tie a large sheet of cloth in the top of some evergreen
tree, in such a way as to form a receptacle to catch the leaves.
Do you catch leaves in winter as well as in summer ?
There are several different kinds of pines, so we must picture
carefully in our minds the foliage of the white pine, for it is dif-
ferent from that of any others. The leaves are soft and very
slender, and from three to four inches long. The base of each
cluster of leaves is at first surrounded by a small sheath-like
40. Shoot of common pitch pine. One -ha If natural size.
body, but this falls away when the leaves are still very young.
A scar is left when the leaves drop and these scars can often be
seen on parts of the branches that are eight or ten years old.
Do the leaves of other kinds of trees make a scar when they fall ?
The white pine cones, in which the seeds are borne, are con-
spicuous objects. They are five or six inches long and slightly
curved. It will be interesting to find out if the seeds ripen the
same year in which they are formed. Perhaps a cone still con-
taining seeds can be obtained. Carefully tear it apart and see
where the seeds are attached. Red squirrels sometimes eat the
pine seeds. A white pine cone, which has shed its seeds, is shown
in Fig. 39.
This kind of pine is found widely scattered in New England,
New York and westward to Minnesota and Iowa and along the
Allegheny Mountains as far south as Georgia ; also in some parts
of Canada. It is a valuable lumber tree.
THE PITCH PINE.
This kind of pine is very different, in many respects, from the
white pine. Let us find some of the differences. Instead of
having leaves in bunches of five, it has them in clusters of three,
and the base of each cluster is inclosed by a
scaly sheath which does not fall away as in
case of the white pine ; neither does the little
scale-like body upon the branch, in the axil of
which the leaf -cluster is borne, fall away, but
it may be found just below the leaf, and even
on branches that are several years old. Some-
times a sheath is found with only two leaves.
We shall want to know, too, how old the
leaves are when they fall. Do they remain on 41- Cone of pitch pine.
One-half natural size.
the tree longer than the white pine leaves do ?
Again, instead of being soft and slender as the white pine
leaves are, we shall find that these leaves are rigid and large in
comparison, and stand out straight from the branches. The
shape of the leaves is also distinct from the white pine needles.
See if you can find any other differences.
A pitch pine branch is shown in Fig. 40. The part between
the tip and A is the past season's growth. Observe the foliage
on the part that is two years old. Part of it has fallen. We
often find it on growth which is older than this ; but in this
specimen there are no leaves on the three-year wood.
The cone of the pitch pine is very unlike that of the white
pine. Fig. 41 gives a good idea of one which has shed its seeds.
Compare this with Fig. 39 ; or, better, examine the two kinds of
cones side by side. The pitch pine cones are sometimes borne in
clusters of two or more and they persist, that is, remain on the
tree for several years after the seeds have ripened and scattered .
152
Notice how the new cones are borne with reference to last sea-
son's growth. Are they attached to the tip of a branchlet? Or
are they closely attached to the side of a branch ? Figs. 42 and
43 will help us answer this question. The little cones in Fig. 43,
near the tip of the twig, are just beginning to form.
The pitch pine
usually grows in
sandy or rocky
soil and is
found in the
United S tates
along the Atlan-
tic coast to Vir-
ginia, along the
mountains to
Georgia, west-
ward to Western
New York, East-
ern Ohio, Ken-
tucky and East-
ern Tennessee.
It has little value
as timber, be-
cause it does not
grow large
enough,
SCOTCH AND AUSTRIAN PINKS.
In the same manner, other pines may be studied. Fig. 44
shows a cone and bit of foliage of the Scotch pine, and Fig. 45
the Austrian pine. These cones grew the past season and are
not yet mature. After they ripen and shed the seeds which they
contain, they will look something like the cone in Fig. 41. The
Scotch pine has short and blue-green needles. The Austrian
pine is coarser, and has long dark-green needles.
There are but two leaves in a cluster on these kinds of pines
and we shall find that the sheath which incloses the base of the
leaf -cluster is more conspicuous than in either the white or pitch
pines. Do the leaves persist in the Scotch and Austrian pines
42. Pitch pine. One-third natural size.
43- Pitch pine, showing young cones. Half natural size.
I
44. Scotch pine. Half natural size.
154
longer than they do in the others we have examined ? Study
the cones of these and other pines.
The Scotch and Austrian pines are not native to this country,
but are much grown for ornament. They can be found in almost
any park, and in many other places where ornamental trees are
grown.
THE NORWAY SPRUCE.
The leaves of spruce trees are borne very differently from
those of the pines. Instead of being in clusters of two or more,
they are single
and without a
sheath at the
base; neither are
there scale-like
bodies on the
branches where
the leaves are
borne. Notice,
too, that the
leaves have a
very short stem
or petiole.
The leaves of
the Norway
spruce are about
one inch long,
although the
length varies
more or less in
different parts of
the tree and in
different trees.
They are rather
stiff and rigid
45. Austrian pine. One-third natural size. and sharp-
pointed. In a general way, the leaves are four-sided, though
indistinctly so.
It will be interesting to study the position which the leaves
155
take on the branches. A hasty glance might give us the impres-
sion that the leaves are not produced on the under side of the
branches ; but a more careful examination will convince us that
there are nearly as many on the under side as on the upper.
The leaves are all pointing outward from the branch and as
nearly upward as is possible. In other words, the leaves grow
toward the light.
We must not forget to see how long the leaves of the Norway
spruce persist and to find out when the leaf-scars disappear.
We can find leaves that must surely be six or seven years old
46. Twig of the common Norway spruce. Half natural size.
and sometimes we can find them even older than this. The leaf-
scars, too, remain along time. The falling of the leaves is illus-
trated in Fig. 46. It shows the extremities of a limb which is
eight years old. The part between the tip and A is last season's
growth ; between A and B it is two years old ; and beyond B is a
part that grew three seasons ago. The section beyond C is six
years old ; from C to D is seven years of age. The four years'
growth of this limb not shown in the drawing was as densely
covered with foliage as is the part shown in the upper figure ; but
there are not many leaves between C and D (seven years old) and
none on the eight-year-old wood (except those on the branchlets,
and these are younger.)
156
The cone of the Norway spruce is nearly as long as that of the
white pine, but it is not so rough and coarse as the white pine
cone is. The cones are usually borne on the tips of small branch-
lets, although occasionally one is found borne in the manner shown
in Fig. 47. The cones usually fall the first winter.
The Norway spruce is not a native of
this country, but, like the Scotch and
Austrian pines, it was introduced from
Europe and is grown very widely as an
ornamental tree. It is the commonest
evergreen in yards and parks.
THE BLACK SPRUCE AND ITS KIN.
There are several different kinds of
spruces which we find growing in
our forests and swamps, and sometimes
these are planted for ornament.
A sprig of foliage and a cone of one
of these, the black spruce, is shown in
Fig. 48. The foliage is not very unlike
that of the Norway spruce, but the cones
are very small in comparison. They are
about one inch long, though they vary
considerably in size. Before they open
they are oval or plum-shape, but when
mature and the scales of the cone have
expanded, they are nearly globular.
They are often borne in clusters, as well
as singly, and persist for many years
after the seeds have fallen. The posi-
tion of the cones will depend upon their age. When young,
they point upward, but they gradually turn downward.
The white spruce resembles the black very closely in general
appearance. The leaves of the white spruce have a whitish or
dusty looking tinge of color and when crushed or bruised, give
forth a peculiar disagreeable odor. The cones vary in length
from an inch to two inches, and in shape are more cylin-
drical or finger-shaped than the cone of the black spruce.
47. Cone of Norway spruce.
Half size.
157
The foliage of the red spruce lacks the whitish tinge of color
of the white spruce and the cones, which are from one inch to
two inches in length, are obovate in shape that is, the
widest place is through the upper part of the cone, and from this
point it gradually tapers to the tip. They seldom persist longer
than the second summer.
The leaves of all these different kinds of spruces vary greatly
in length, thickness and sharpness of point, according to the part
of the tree on which they grow, and their surroundings. The
shedding of the leaves on these or other spruces can be determined
as easily as in the Norway spruce.
These three spruces like a cold climate and grow in many
sections of northern United States and Canada and farther
48. Black spruce. Half natural size.
south in the mountains. They are sometimes all found growing
together, but the black spruce likes best the damp, cold swamps,
while the others grow best on the drier and better drained
lands. The black spruce is commonest. The red spruce is
least known.
THK BALSAM FIR.
This is another evergreen tree which grows naturally in the
cold, damp grounds of the northern United States and Canada, and
to some extent in the eastern states as far south as West Virginia.
The foliage is borne in much the same manner as that of the
spruces ; yet there are interesting differences in the characters of
these two kinds of leaves. Perhaps the most noticeable difference
is in the shape ; and the color of the fir leaves will attract our atten-
tion because the under side is a silvery color, while the upper side is
green. What is the nature of the tip of the leaf? and how does
158
it compare with the pines and spruces in this respect ? Does the
leaf have a stem or petiole? or is it attached directly to the
branches without any stem? How are the leaves shed ?
The cones are about three inches long and present a rather
delicate appearance. It will be interesting to determine the
position of the cones, that is, the direction in which they point,
and to learn if it is the same when they are young that it is after
they have matured.
The grayish colored bark of the trunk and limbs bears many
*' blisters " from which Canada balsam is obtained.
THE HEMLOCK.
A hemlock twig is an interesting object. It may have many
characters in common with the spruce and fir, yet the impression
which we get from it, or from a large hemlock tree, is entirely
distinct. The arrangement of the leaves and the gracefulness of
the drooping branchlets are most pleasing. We are lead to
examine it more closely. We notice that the leaves appear to be
borne in two more or less regular rows, one on each side of the
branch or twig ; but in reality they come from all sides of the
branch, and it is the position which the leaves assume that gives
this two-rowed appearance.
The leaves have a short petiole or stem, and this stem rests
along the side of the branchlet in such a direction that the leaves
are placed in single rows on either side of the branch. The
petioles of the leaves are nearly parallel with the branch while
the leaves often make a decided angle with the petiole. This
fact can best be brought out by carefully examining a small twig.
While we are noting the arrangement of the leaves on the
branchlets, we should also take notice of the points of similar-
ity and difference between these leaves and the spruces and firs.
We shall find that there is more in common, at least so far as
shape and color are concerned, between the hemlock and fir than
between the hemlock and spruce.
The small delicate cones, borne on the tips of the branchlets, will
also attract our attention (Fig. 49.) We may wonder at their small
size, for they are only about three-quarters of an inch long, and
very delicate, yet a second glance at the tree will impress us with
159
the number of cones which the tree bears : and we conclude that,
although the cones may be small, yet there are so many of them
that there will be no lack of seeds.
It is more difficult to trace the age of a hemlock limb than of
many other kinds of trees, yet we can easily determine that many
of the leaves are several years old when they fall.
The bark of the hemlock is used in tanning leather. The tree
is much used for lumber. Where does it grow ?
THK ARBOR-VIT.^.
One might almost wonder, at first sight, if the arbor-vitse
(often, but wrongly, called white cedar) has any leaves at all.
Spray of the hemlock. Two-thirds natural size.
It does possess them, however, but they are very different in size
and shape from any of the others which we have examined.
They are small scale-like bodies, closely pressed together
along the sides of the branchlets, in four rows. L,eaves pressed
to the branches in this manner are said to be "appressed."
The leaves of the arbor- vitae are so close together that they overlap
one another. The leaves are of two distinct shapes, sometimes
known as the surface leaves and the flank leaves. The former are
located on what appears to be the flattened surface of the branch-
lets, while the latter are on the sides or edges. See Fig. 50.
If we carefully look at the leaves, we shall notice a raised spot
i6o
near the point or tip. This is said to be a resin gland. This
gland can be seen more plainly on the surface leaves that are
two years old.
Most of the leaves persist for at least two and sometimes
three years ; but even older ones can be found. These older
leaves, however, do not exist as green active leaves, but merely as
dried up and lifeless scales. These lifeless leaves, are probably
detached from the branches by the forces of nature.
The Arbor-vitae. Nearly full size.
The cones are even smaller than the hemlock cones. They are
borne in the axils of the leaves in the same manner as the branch-
lets and are not conspicuous unless one is close to the tree.
The arbor- vitae is much planted for hedges and screens, as well
as for other ornamental purposes. There are many horticultural
varieties. The tree is abundant in a wild state in New York.
Summary on the Kinds of Common Evergreens.
The white pine (Pinus Strobus). Leaves in clusters of five, soft
and slender ; cones five or six inches long, slightly curved ;
bark smooth except on the trunks and larger limbs of old
trees, where it is fissured.
The pitch pine (Pinus rigida). Leaves in clusters of three, from
three to four inches long, rather rigid ; cones two to three
inches long, often in clusters of two or more but frequently
borne singly, persisting long after the seeds have been shed ;
bark more or less rough on the young growth and deeply
fissured on the trunks of old trees.
The Scotch pine (Pinus sylvestris). Leaves usually in clusters of
two, from two to four inches long, rigid, of a bluish-green
hue when seen in a large mass on the tree ; cones two to three
inches long and the scales tipped with a beak or prickle.
The Austrian pine (Pinus Austriaca). Leaves in clusters of two,
five or six inches long and somewhat rigid, dark green in
color and persisting for four or five years ; cones about three
inches long, conical in shape and scales not beaked or pointed
as in the Scotch pine.
The Norway spruce (Picea excelsa). Leaves borne singly, about
one inch long, dark green, four sided ; cones about six inches
long, and composed of thin scales, and usually borne on the
tips of branchlets. The small branches mostly drooping.
The black spruce (Picea nigra). In general appearance, this is
not very unlike the Norway spruce, but the small branches
stand out more horizontally and the cones are only one or
one and one-half inches long, recurving on short branches.
The cones persist for several years after shedding the seed.
71ie white spruce (Picea alba). Leaves about one inch long,
having a glaucous or whitish tinge ; twigs stout and rigid,
of a pale greenish white color ; cones from one to two and one-
half inches long, more or less cylindrical or " finger-shape,"
and easily crushed when dry.
The red spruce (Picea rubra). The foliage lacks the whitish
tinge of the white pruce and is of a dark or dark yellowish
color ; twigs stouter than those of the black spruce and not
162
so much inclined to droop ; cones about one inch long,
obovate and usually falling by second summer.
The hemlock (Tsuga Canadensis). Leaves about one-half inch
long, flat with rounded point, green on the upper side, whit-
ish beneath, and borne on short appressed petioles ; cones
about three-quarters of an inch long, oval or egg-shape, and
borne on the ends of small branchlets and often persisting
for some time.
The balsam fir (Abies balsamea). Leaves narrow, less than one
inch long, borne singly, very numerous and standing out from
the branchlets in much the way of the spruce ; cones about
three inches long, cylindrical, composed of thin scales and
standing upright on the branches, or recurved ; bark smooth,
light green with whitish tinge.
The arbor-vita (Thuya occidentalis) . Leaves very small, scale-
like and over lapping one another in four rows, adher-
ing closely to the branchlets ; the cones oblong and small, a
half inch or less in length, and composed of but few scales.
For further information respecting nature-study, address,
Bureau of Nature- Study*
Cornell University,
Ithaca, N. Y.
Or,
I. P. Roberts,
Director College of Agriculture.
L. H. Bailey,
Chief of Bureau of Nature- Study and Reading -Course.
John W. Spencer,
Deputy Chief.
Bulletin 68. August, 1894.
Cornell University Agricultural Experiment Station.
HORTICULTURAL DIVISION.
The Cultivated Poplars;
WITH REMARKS UPON THE PLANTING
OF GROUNDS.
By L. H. BAILEY.
PUBLISHED BY THEC UNIVERSITY.
ITHACA, N. Y.
1894.
ORGANIZATION.
BOARD OF CONTROL:
THE TRUSTEES OF THE UNIVERSITY.
STATION COUNCIL.
President, JACOB GOULD SCHURMAN.
Hon. A. D. WHITE, - Trustee of the University.
Hon. JOHN B. BUTCHER, - President State Agricultural Society.
Professor I. P. ROBERTS, - Agriculture.
Professor G. C. CAUDWELL, - Chemistry.
Professor JAMES LAW, - Veterinary Science.
Professor A. N. PRENTISS, Botany.
Professor J. H. COMSTOCK, - Entomology.