hackberry is an elm. It is a member of the family but is of a different
genus, and it is the sole representative of its genus in the known
world. There is only one kind of planertree, with no nearer relatives
than the elms on one side and hackberry, sugarberry, and palo blanco on
the other. Except those kinsfolk, it is alone on earth. The name is in
honor of Johann Jacob Planer, a German botanist whose efforts did much
for science nearly two hundred years ago. The name of the species
_aquatica_, recognizes the tree’s habit of growing where water is
abundant. It is a swamp species, or rather, it prefers situations
subject to periodic overflow. It looks like an elm, and that has led
people to call it water elm. That is the name by which it is usually
known in Florida. In Alabama it is called the American planertree, which
is an unnecessary restriction, since there is no planertree except this
one. The Louisiana French gave it the name plene, and the abridgement of
its name is yet heard in that state. In North Carolina it has acquired
the name sycamore, but without good reason. It does not look in the
least like sycamore.
It has the leaf of an elm, and it resembles that tree in bark, and
somewhat in general form. The layman detects the first important
difference when he examines the seeds. Those of the elms have wings, but
the planertree’s are without those appendages, and they would be useless
if it had them, unless they were as large as the parachute of the
basswood seed. The planertree bears a sort of nut, a third of an inch
long, and too heavy to be transported far on the ordinary membranous
wings of tree seeds. Water is doubtless the principal agent in carrying
the seeds from place to place. Probably few of them are transported far,
because the water about the trees is generally stagnant; and, besides,
the species does not seem to be extending its range or increasing in
numbers.
The planertree has a history. If the terms which the Roman historian
Tacitus applied to people, could be applied to trees, it might be said
of this species, as he said of certain tribes: “The cowards fly the
farthest and are the last survivors.” The planertree is now found only
in certain southern swamps, from North Carolina to Florida, and west to
Missouri and Texas. In former periods, as is shown by the records of
geology, there were several species, and they had a wide range over
portions of the northern hemisphere. They appear to have been a strong
group of trees, able to hold their ground with the best inhabitants of
the forest. They were in the Rocky Mountains, and far north in Alaska.
They were in Europe also, or were represented there by some very similar
species.
For some reason which is not definitely known, they lost out when
competition with other trees became keen, and in the course of long
periods of time they disappeared from their former ranges in the North
and West. They took to the swamps, just as the tribes of which Tacitus
spoke, took to the morasses when they could no longer face their enemies
on open ground. It was a far cry from Alaska to the Chattahoochee swamps
in Florida, yet that was where A. H. Curtis and Charles Mohr went to
procure typical planertree specimens for the tests which Sargent made of
American woods.
It has been suggested that tree species which have lost out in
competition for ground, have been those which were at some decided
disadvantage in the matter of getting their seeds properly scattered and
planted. The case has not been proved, because there are as many facts
and as much argument against that hypothesis as for it. The bigtrees of
California are a noted example of a species which lost out and retreated
to a corner, yet their seeds fly like birds. Plainly, something besides
winged seeds is needed to keep the species in the fight. However, it is
not difficult to see that the planertree, with wingless seeds and of so
little use as food that no bird or rodent will carry them or bury them,
has been much handicapped in the long contest which has crowded it from
the arctic circle to the cotton belt.
It has the habits of the subdued and conquered tree. It has adapted
itself to swamps where few species can grow, and where competition for
light and room is reduced to a minimum. Yet, even there, it is content
to take the leavings of more ambitious species. The crowns make little
effort to rise up to the light, for which many other trees battle during
their whole existence. The planertree’s low, broad top of contorted
branches places it perpetually in the shade of any other trees which
overtop it.
The wood of the planertree is lighter in weight, poorer in fuel value,
weaker, and more brittle than the poorest of the elms. The annual ring
lacks the rows of large open pores common in all the elms, but it has
many small pores scattered through the whole year’s growth. It is not
easy to note a difference between the springwood and that which grows
later. The wood is soft, light brown in color, and the nearly white
sapwood is thick. It is often, perhaps generally, a tree of fairly rapid
growth, and since it does not reach large size, it is probably
short-lived, but exact information along that line is lacking.
The tallest trees seldom exceed a height of forty feet and a diameter of
two. It is evident that a tree of that size and form does not tempt the
lumberman to much exertion to procure it. An examination of reports of
sawmill operations and of the utilization of woods by shops and
factories in the southern states has failed to find a single instance
where the planertree has been reported in use for any purpose whatever.
Doubtless, trees are sometimes cut and the lumber gets into the market,
but not under its own name. The species is interesting for reasons other
than that it ever has had or ever can have a place in the country’s
lumber industry.
WING ELM (_Ulmus alata_), which is the smallest of the elms, is
plentifully supplied with names, but in most parts of its range it
is known as wing or winged elm. It is also called wahoo or wahoo
elm, and the West Virginians have named it witch elm; the North
Carolinans refer to it often as simply elm; from Florida to Texas
some call it cork elm; in Alabama it is water elm; in Arkansas
mountain elm; while in other regions it is corky elm, small-leaf
elm, and red elm. Some of these names are self-explanatory. Wing elm
does not relate to a winged seed, but to winged twigs. That
characteristic of the tree is very prominent. The wings consist of
flattened keels along opposite sides of the branches. A twig no more
than a quarter of an inch in diameter may be decorated with wings
half an inch or more wide, making the twig four or five times as
wide as it is thick. As the twig enlarges, the wings do not broaden
in proportion. The lowest branches and those nearest the trunk are
most generously furnished with wings. They appear to be entirely
ornamental, for it is not known that they serve any useful purpose.
The growth is different from those which give cork elm its name. The
latter occur on the large branches, often in the form of isolated
protuberances, but the wings are fairly continuous for a foot or
more, except that they terminate abruptly at the nodes, but
recommence immediately after. Branches less than a year old seldom
have wings. The name wahoo appears to have lost its etymology if it
ever had any. Dictionaries tell what it means, but they shy at its
origin. It is a southern word which is applied to this elm, and also
to other trees, and occasionally it means a fish instead of a tree.
Some would trace it to the cry of an owl, others to a name in
Gulliver’s Travels, with a slight change in spelling.
Wing elm at its best is about fifty feet high and two in diameter;
but much of the stand is small. The best occurs west of the
Mississippi river. The range extends from Texas to Virginia, south
to Florida, and north to Illinois. In Texas it is a fairly important
wood in furniture factories, the annual supply being about a million
feet. It is used by turners for table legs. In an investigation of
the uses of the wood, the same difficulty is encountered that makes
difficult a study of the uses of all the elms--conflict and
uncertainty of names. There are few regions in the hardwood areas of
this country which produce one elm and no more; and after all
practical means of identification are resorted to, there is often
doubt and uncertainty concerning the exact species of elm lumber
found in use. Fortunately, it generally makes little difference,
because anyone of them is good enough for ordinary use. Wing elm is
extensively planted for shade along the streets of towns in the
lower Mississippi valley, but more frequently on the west side of
the valley. When the trees grow in the open they develop broad
crowns, and the branches, even of comparatively small trees, are
long enough to reach well over the sidewalks, and cast satisfactory
shade. The dark-colored winged twigs add much to the ornamental
value of the street trees.
FREMONTIA (_Fremontodendron californicum_) is not botanically in the
elm family, but it is popularly known as slippery elm in the region
where it occurs, and for that reason it is here given place among
the elms. It is known also as leatherwood. It is a California
species, ranging among the lower mountains and higher foothills in
dry, gravelly soils, from the Mexican boundary five hundred miles
northward in the state. The mucilaginous inner bark tastes like that
of the true slippery elm. The shape of the leaf much more resembles
sycamore than elm; and it is an evergreen. It bears a bright yellow,
roselike flower, and the seeds are small, reddish-brown. The wood is
fine grained, clear reddish-brown, with thick, whitish sapwood. It
is very soft. The tree attains its largest size among the foothills
of the Sierra Nevada mountains, but even there it is too small to
have much economic value, seldom exceeding thirty feet in height and
a foot in diameter. Its most important use is as a forage plant for
cattle and sheep. In that particular it resembles slippery elm in
northern woods. The tree is occasionally planted in the eastern
states and in Europe for ornament. In its native range it grows
slowly.
[Illustration]
HACKBERRY
[Illustration: HACKBERRY]
HACKBERRY
(_Celtis Occidentalis_)
Hackberry is a common name for this tree in nearly all parts of its
range, but it has other names. It is sometimes confused with sugarberry
(_Celtis mississippiensis_). They call it nettle tree in Rhode Island,
Massachusetts, Delaware, and Michigan, and in Tennessee it is known as
American nettle-tree. In Vermont it is hoop ash; in Rhode Island
one-berry; hack-tree in Minnesota, and juniper tree in New Jersey.
The name hackberry is not of American origin. It dates far back in the
languages of western Europe and is believed to have the same origin as
the word haw, which, in its turn meant hedge. If that etymology is
correct, the word really means hedge berry, which is not an
inappropriate name for the tree. The name is sometimes applied to a
small bird cherry in Europe. The New Jersey name juniper-tree is in
recognition of the resemblance of the berries to those of red cedar or
red juniper. No reason has been assigned for the name nettle-tree.
Its range covers about 2,000,000 square miles in the United States
besides part of Canada. It grows from the Atlantic on the coast of New
England to the tide water of the Pacific on Puget sound; in southern
Florida and in Texas. It is not found in pure stands, but often as
single trees far apart. This is the case in the northeastern part of the
United States in particular where probably not more than one tree might
be found in a whole county. Frequently the people in the neighborhood do
not know what the tree is, and suppose it is the last representative on
earth of some disappearing species.
It is far from being a disappearing tree. Not only is it widely
dispersed over the United States, but related species are scattered
through many countries of the old world, from Denmark to India. There
are said to be between fifty and sixty species, only two of which are in
the United States.
It has been claimed by scholars that the lotus referred to by ancient
writers was the hackberry. It was reputed to cause forgetfulness when
eaten, but the claim was fictitious, for the fruit does not produce that
effect. It is not now regarded as human food. Tennyson deals with the
fiction very beautifully in the poem “Lotus Eaters,” but he took
liberties with botany when he represented fruit and flowers on the same
branch; for, though the berries hang several months, they drop before
the next season’s flowers appear.
The hackberry belongs to the elm family, being of the same relation as
the planertree. The leaves resemble those of the elm, but are more
sharply pointed. The fruit is usually classed as a berry. It ripens in
September and October, but remains on the tree several months, becoming
dry. It is about one-fourth inch long, dark purple, with a tough, thick
skin, and with flesh dark orange. Most of the pale brown seeds are eaten
by birds.
The tree varies greatly in size. In some remote corners of its immense
range it is little more than a shrub, while at its best it may attain a
height of 100 feet and a diameter of three or four. Its average size is
about that of slippery elm. The bark varies as much in appearance as the
tree in size. Sometimes it has the smooth surface and pale bluish-green
appearance that suggest the bark of beech; again it is darker and
rougher, like the elm. It frequently exhibits the harsh warty bark which
is peculiar to the hackberry, and when present it is a pretty safe means
of identification. The warts may be conical, oblong, or sharp-pointed,
and probably an inch in height. When closely examined, most of them are
found to consist of parallel strata of bark which may usually be pulled
off without much difficulty. The warts are a decided disadvantage to the
tree in some of the low swampy districts of Louisiana where Spanish moss
is a pest. This moss (which is not a true moss), is propagated
principally by tufts and strands which are carried by wind until they
find anchorage among the branches of trees where they increase and
multiply at a rapid rate until they finally smother or break down the
unfortunate tree which supplied a lodging place. The hackberry’s warts
catch and hold every flying strand of moss that touches them, and
hundreds, perhaps thousands of pounds of it may accumulate on a single
tree. The grayish-green color of the moss often exactly matches the hue
of the tree’s bark.
The reported annual cut of hackberry lumber in the United States is less
than 5,000,000 feet. That can be only a fraction of the total output.
Few mills report it separately, but list it as ash. The wood looks more
like ash than elm. It is heavy, but only moderately hard and strong. Its
color is more yellowish than ash, but the annual rings of growth
resemble that wood. The sapwood is thick, and growth is rapid where
conditions are favorable.
It is doubtless used by industries in thirty states or more, but
comparatively few factories report it. In Texas it is listed in the box
and crate industry. In Louisiana it rises to more importance, for that
is the region where the tree attains its best. Slack coopers make kegs,
tubs, and barrels of it; vehicle manufacturers convert it into parts of
buggy tops and the running gears of wagons; it serves for furniture and
interior finish; and it takes the place of ash for hoe handles and parts
of agricultural implements. The uses are nearly the same in
Mississippi, but it is used there for rustic seats and other outdoor
furniture. In Missouri it is found suitable for cart axles, saddle
trees, stitching horse jaws, and wagon beds. In Arkansas it goes with
ash into flooring, and interior finish for houses. Illinois builders
work it into fixtures for stores. In Michigan it serves the same
purposes as in Texas, baskets, boxes, and crates. These examples
doubtless are representative of its uses wherever the tree is found in
commercial quantities. The wood is not durable in contact with the soil.
It is also liable to attack by boring insects if logs are allowed to
retain their bark.
The hackberry has been planted to a small extent as a street tree in the
southern towns, but it is not as popular as the elms and oaks. It will
never occupy a more important position in the country’s lumber industry
than it holds at present. It is a tree which, for some reason, inspires
little enthusiasm in anybody; but nature takes care of it fairly well,
and the small sweet drupes which it bears are a guarantee that the
species will not want for seed carriers as long as birds continue to
have access to its branches in winter.
SUGARBERRY (_Celtis mississippiensis_) is frequently mistaken for
hackberry even by persons who ought to be able to distinguish them.
Botanists formerly confused the two, and probably some insist still that
sugarberry is only a variety of hackberry. The leaves generally have
smooth margins, and that would differentiate the tree from the hackberry
were it not that sometimes the sugarberry has serrate leaves. The drupes
are bright orange red and are usually smaller than the purple fruit of
hackberry. As for the wood of the two species, it is not easy to tell
one from the other. The sugarberry’s range is not one-third as extensive
as hackberry’s, but covers some hundreds of thousands of square miles in
the southeastern quarter of the United States. Its northern limit is in
Illinois and Indiana where it occupies rich bottom lands and the banks
of streams. It reaches its largest size in the lower Ohio river basin,
grows southward into Florida and west into Texas, Arkansas, and
Missouri. It crosses the Rio Grande into Mexico, appearing to outstrip
the hackberry in that direction. It outstrips it in another direction
also, for it is found in the Bermuda islands. The French of Louisiana
called it bois inconnu, or the unknown wood.
This tree shows a marked tendency to run into varieties, and cultivation
would probably develop the tendency. The differences between the species
and the varieties are plain enough to the systematic botanist, but are
such that the lumberman or other ordinary observer would scarcely notice
them. The variety which has been named _Celtis mississippiensis
reticulata_, but without any English name except sugarberry, is a tree
forty or fifty feet high, covered with blue-gray bark, very rough. It
ranges from Dallas, Texas, to the Rio Grande and westward into New
Mexico, Arizona, and Utah, and into southern California and Lower
California. In eastern Texas it is found on dry limestone hills, but
westward only in mountain canyons in the vicinity of water. In the
southern part of Texas this tree is usually known as palo blanco, but
those who apply that name have no idea that it is a variety of
sugarberry but suppose it is a tree peculiar to their region. In Cameron
and Hidalgo counties, Texas, either because an extra good quality grows
there, or because some opinion exists in its favor, it is liked for
wagon material, and occasionally is turned for table legs and other
parts of furniture. It is quite common in that part of Texas as an
ornamental tree in yards and along streets of small towns. The whiteness
of the bark is the most striking feature.
[Illustration]
WHITE ASH
[Illustration: WHITE ASH]
WHITE ASH
(_Fraxinus Americana_)
This tree is generally called white or gray ash, or simply ash. American
ash is a translation of its botanical name and is not often used in
business transactions in this country. In some parts of the South the
term cane ash is occasionally employed, but there seems to be no
agreement among those who use the name as to what it means. This is the
common ash in the lumber trade. There are more than a dozen species in
the United States, but white ash goes to market in larger amounts than
all others together. This is known in a general way, but exact figures
cannot be given, because statistics of the cut of different species of
ash are not kept separate.
The range of this tree covers at least a million square miles, and all
or part of every state east of the Mississippi river and west of it from
Nebraska to Texas. It is reported cut for lumber in thirty states. The
various ashes are lumbered in thirty-nine states. Ash does not occur in
pure stands but is scattered in forests of other species, sometimes
growing in small clumps. It is difficult to name an average size for the
tree, because climate and soil control the growth over a large area
where conditions vary. Trees 120 feet high and six feet in diameter are
said to have stood in the primeval forests in the lower Ohio valley; but
logs four feet through are seldom seen now. Trees seventy or eighty feet
high and three in diameter are above the average in any region where
this tree is now lumbered. Some of the old planted trees of New England
are five or six feet through, and are finely proportioned, but growing
as they do in the open, they have larger crowns than are found in forest
trees.
All species of ash have compound leaves, and those of white ash are from
eight to twelve inches long. The under sides of the leaflets are white,
and some persons have this fact in mind when they call the species white
ash, while others refer to the bark, and still others to the wood. It is
a characteristic of the tree that most of the leaves grow near the ends
of the limbs. For that reason the crown appears open when viewed from
below, and the larger limbs and branches are naked. The leaves demand
light, and they arrange themselves on the extremities of the limbs to
get it. When the tree is crowded, it sheds its lower limbs and its crown
rises rapidly until it reaches abundance of light. This produces long
trunks in forests.
The boles are often not quite straight, but have several slight crooks,
yet keep close to a general perpendicular line. That form is due to a
peculiarity of growth. The leading shoot of a growing ash has more than
one terminal bud. If a side bud pushes ahead, the stem leans a little in
that direction; next, a bud on the other side may gain the ascendancy,
producing a slight lean for a few years in that direction; or two side
buds may develop simultaneously, causing a forked trunk. Mature trees
often carry the history of these peculiarities of growth.
The seeds of white ash are equipped for moderate flight. The wing is
large, but the seed attached to the end of it is heavy enough to give it
a sharp tilt downward when it begins its flight through the air, and it
generally shoots at a steep angle toward the ground. It is not apt to
whirl through the air with a gliding motion like a maple seed.
Consequently, ash seeds are not great travelers. They are dispersed with
economy, however, for all do not come down at once, but many hang on the
tree for months, and a few go with every strong wind, thus getting
themselves scattered in every direction. Their power of germination is
low, and only about forty per cent of seeds are fertile. This is due to
the fact that pistillate and staminate flowers do not grow on the same
tree, and fertilization is imperfect.
The importance of ash in the industries of the country does not depend
on the quantity but the quality of the wood. Although the various
species are produced in thirty-nine states, as shown by mill statistics,
the total yield is less than 250,000,000 feet a year. That is exceeded
by several woods, among them hickory, elm, beech, basswood, chestnut,
and even larch.
The wood of ash which has grown rapidly is generally considered superior
to that of slow growth. The reason is found in the fact that trees of
slow growth do most of their growing early in the season, and the wood
is porous; but trees of rapid growth lay summerwood on abundantly, and
it is dense. Few species show a sharper line between spring and
summerwood than ash, for which reason the annual rings are clear-cut and
distinct. What figure ash has is produced by the growth rings, and not
by medullary rays. Quarter-sawing brings out no additional beauty.
Slight crooks in many logs produce a moderate cross grain in lumber,
which gives to finished ash its characteristic figure or grain. When
straight-grained wood is wanted, as when it is for tool handles and
oars, logs without crooks are selected.