the common cottonwood is in the East, and hundreds of thousands of
staves are made yearly. It is in demand for the manufacture of flour
barrels and those intended for other food products.
Trunk makers use it in three-ply veneers for the bodies, trays, boxes
and compartments of trunks and for suit cases. Though soft and light, it
is very tough, and sheets of veneer with the grains placed transversely
resist strains much better than solid wood of the same thickness.
Vehicle makers employ black cottonwood for the tops and shelves of
business wagons. Another of its uses is as bottoms of drawers for
bureaus, wardrobes, and chiffoniers, and as partitions in desk
compartments. A full line of kitchen and pantry furniture is made wholly
or in part of this wood in the regions where it is cheap and abundant.
The cottonwoods belong to a very ancient race of broadleaf trees, and
like several others, they seem to have had their origin, or at least a
very early home, in the far North, where intense cold now excludes
almost every form of vegetable growth except the lowest orders. The
Cretaceous age saw cottonwoods growing in Greenland. The cotton which
then, as now, carried the seeds and planted them fell on more hospitable
shores then than can now be found in the far frozen North. The genus was
not confined to the arctic and subarctic regions, however, for there
were cottonwoods at that time, or later, in more southern latitudes.
There were many species in the central portion of this country, and also
in Europe, long before the ice age destroyed all the forests north of
the Ohio and the Missouri rivers. Some of the old species long ago
ceased to exist, but others appear to have come down to the present time
without great change.
The cottonwood shows wonderful vitality, which is doubtless a survival
of the characteristic which enabled it to come down from former geologic
epochs to the present time. A damaged and mutilated tree will recover. A
broken limb, thrust in the ground, will grow.
BLACK POPLAR (_Populus nigra_) is quite distinct from black
cottonwood, though both belong to the same family. The latter is a
Pacific coast species, while the former belongs in Europe, although
it may have been introduced into that country from Persia or some
other eastern region. It is common in the United States, on account
of having escaped from cultivation. The best known variety of this
tree is the Lombardy poplar (_Populus nigra italica_). It is easily
recognized by the characteristic attitude of the branches which grow
upward close against the trunk. The crowns of the trees are very
long and slender, sometimes not ten feet across though fifty feet
high. Their slimness gives the trees the appearance of being much
taller than they really are. They were formerly popular for planting
along lanes and in door yards. Their slender and pointed spires cut
the horizon with a peculiar effect. Planting is less common now than
formerly, because people have come to know the trees better. They
are probably the most limby of all the members of the cottonwood
group. The long trunks are masses of knots when the limbs have been
trimmed away, and any desire to make lumber of the trees is apt to
be discouraged, though not infrequently logs go to local sawmills,
and farmers haul the boards home to put them to some use about the
place. In Michigan and Ohio, box makers use the lumber for the
rougher and cheaper articles which they turn out.
The most discouraging thing about Lombardy poplar is the tendency of
the trees to send up sprouts. The living trees do it, and the stumps
are worse. The sprouts are not confined to the ground immediately
round the base of the tree, but spring up many feet or many yards
distant, until they produce a veritable jungle. Years are often
required to complete their extermination by grubbing and cutting.
WHITE POPLAR (_Populus alba_) is a European species but has become
naturalized in the United States. It is widely planted as a shade
tree, and has escaped from cultivation. It may be known by the white
undersides of its small leaves, and by its yellowish-green bark
which remains smooth, except on large trunks. It is not yet
important as a source of lumber, but the vigor of its growth
indicates that it may sometime become so. The wood is soft, white,
and light. Some persons consider the tree objectionable as an
ornament because of its habit of sending up sprouts from the roots,
and because its woolly leaves collect dust and smoke until they are
almost black by the end of summer.
[Illustration]
MANGROVE
[Illustration: MANGROVE]
MANGROVE
(_Rhizophora Mangle_)
The mangrove family is large and widely scattered, but only one member
has gained a foothold in the United States, and it occupies only limited
areas in south Florida, at the delta of the Mississippi, and on the
coast of Texas. The family’s fifteen genera are confined to the tropics,
with a little overlapping on the temperate zones. The botanical name
_Rhizophora_ refers to the tree’s peculiar roots, and _mangle_ is the
Spanish for mangrove. This is one of the few trees in this country which
are known by a single name. It is always called mangrove, and attains
its best development in Florida.
The leaves hang two years, are from three to five inches long and one or
two wide. Flowers are not showy, but they are nearly always present,
blooming the year round, the yellow blossom about an inch in diameter.
The fruit proper is about an inch long, but its habit of sprouting while
still on the tree and sending down a long stem-like root, gives the
impression that the fruit is several inches long, sometimes a foot.
It is not an easy matter to state the average size of mangrove trees.
Peculiar habits of growth make measurements difficult. Neither is it
easy to tell where a tree begins and where it ends. Mangrove thickets
along some of the rivers of south Florida, within the influence of tide
water, are strange forms of vegetation. If the foliage alone is
considered from a little distance, it reminds one of a row of fig trees
in Louisiana or California. The color and general appearance suggests
fig trees. A nearer approach reveals beneath the crowns a mass of roots,
stems, and limbs, joined with the ground beneath and the crowns above.
In addition to these, there are many others that dangle from above, like
rope ends, some nearly touching the ground, others several feet above.
These are roots or limbs, by whichever name one cares to call them. They
grow from overhead branches, and strike for the ground. When they touch
the soil, they quickly anchor themselves, and become stems. They then
look like slender poles set as props under the branches of an overladen
fruit tree.
This strange habit of growth gives the tree its character. Most
mangroves stand in water. They fringe the banks of rivers and bayous,
extending the fringe as far as the water is shallow. Growth of that kind
is generally from ten to twenty feet high, and the largest stems from an
inch in diameter up to three or four; but these dimensions cannot be
taken as limits to size. Sometimes the trees are sixty or seventy feet
high, but those which stand in water seldom reach that size. Trees
which have their beginning in the water sometimes end their days high
and dry on the land.
The mangrove is a land builder. The sycamore and willow are land
builders on a small scale, along northern water-courses, but mangrove
excels them a hundred or a thousand fold where it grows on the low
shores of Florida. The seed is prepared for land-building work before it
drops from the tree. It sprouts a long, peculiar root--it looks like a
very slender, big-ended cucumber--the large, heavy end down. This
attains a length of several inches or a foot. When it drops from the
branch, the end sticks in the mud and takes root, grows, and produces a
tree. But generally it falls in water, and not on a mud bank. In that
case it floats away, the heavy end down, the light end barely appearing
on the surface. Winds and currents drive it about until the lower tip
finally touches bottom in some shallow place. There it takes root, and
unless circumstances are extremely adverse, it holds fast, finally
becomes a tree, sends branches down from above to take root at the
bottom of the water, and a clump is produced. The tangled mass of stems
and roots catches driftwood and mud, resulting finally in a little
island, and later the island is joined to the mainland. Thus the land is
built. Many large flats in Florida owe their origin to this tree. When
land is permanently above water, the mangrove loses, to some extent, its
ability to send roots down from the limbs. Nature seldom does something
for nothing, and since the mangrove’s aerial roots no longer serve a
useful purpose in nature’s economy, they are dispensed with. Trunks then
reach much larger size, and become timber instead of thickets. The
accompanying picture shows a mangrove that no longer stands in water,
and its habit of growth is changing.
Thickets of mangrove are useful, not only in building new land, but in
protecting that already built. Frequently the force of waves is broken,
which otherwise would destroy low shores. Tremendous seas, in time of
storms, will roll over thickets of mangrove without uprooting them or
breaking the stems. Again nature’s fine engineering is apparent. When
men build lighthouses which must endure the shocks of waves, they have
learned to construct them of open beams and lattice work. The wave
passes through without delivering the full impact of the blow to the
structure. No solid masonry will stand what a comparatively light open
frame will endure without injury, because it allows the waves to pass
on. A large wave may strike with a force of 6,000 pounds to the square
foot. The mangrove thickets are like the open-framed lighthouse--they
let the waves pass through and spend their force gradually beyond, but
they hold the shore against washing.
Admirable and wonderful as is nature’s provision for protecting the
land by a fringe of lattice work of branches and stems, the marvelous
efficiency of the provision has been greatly increased in another way.
Suppose, for illustration, that cottonwood instead of mangrove formed
the protective thickets along stormy shores. The first hour of heavy
seas would reduce the trees to fragments. The weak, brittle trunks and
limbs would quickly break to pieces. But mangrove passes through storm
after storm unharmed. It is scarcely believable that accident accounts
for the fact that the best wood for the place is in the place; but it is
probable, rather, that ages of development and natural selection gave to
mangrove the qualities which make possible the accomplishment of its
work. It is one of the strongest, and as far as available data may be
depended upon, it is absolutely the most elastic wood in the United
States. Shellbark hickory is rated high in both strength and elasticity;
but mangrove rates higher. Sargent gives hickory’s measure of elasticity
at 1,925,000 pounds per square inch; but mangrove’s is 2,333,000 pounds.
It is thus fitted in the highest manner to perform the work needed. It
plants itself in the right place; develops stems which will endure most
and suffer least; possesses enormous strength for resisting force, yet
is so extremely elastic that the force of waves is exhausted upon the
trunks and branches without flattening them upon the ground or crushing
them. Few things of the vegetable world show more perfect adaptation to
environment. The wood’s very heaviness seems to add one more quality
fitting it for its place. When a trunk falls in the water, it does not
float away as most trees would, but sinks like iron, lies on the bottom,
helps to hold the forming island or bar in place, and in its death as in
its life it is a land-builder. Its efficiency in that particular is
increased by the fact that it is little affected by marine borers which,
in the warm, brackish waters, usually destroy wood in a short time.
Mangrove is not important commercially, though it is used for a number
of purposes. The wood weighs 72.4 pounds per cubic foot, takes good
polish, though it is inclined to check in drying; it contains many small
pores; medullary rays numerous and thin; color reddish-brown streaked
with lighter brown. The principal use of the bark is for tanning and the
trunks for piles. It is well fitted for fence posts, but not many have
been used in the region where it grows. It rates high as fuel, but its
great weight increases transportation charges if the haul is long.
Tanbark peelers in Florida have cut much of the large mangrove forest.
They took the bark, and abandoned the trunks. There is no likelihood
that the species will be exterminated. Much of the growth is practically
inaccessible, and the trunks are too small to tempt bark peelers, and
cordwood cutters find plenty of material more convenient.
OTHER SPECIES.--Two other trees of this country are called mangrove
though they are not even in the same family. One is the black
mangrove (_Avicennia nitida_), called also blackwood and black tree.
It is a Florida species of the family Verbenaceæ, and has some of
the mangrove’s habits. It takes root and grows on muddy shores and
is a land builder. The largest trees are sixty or seventy feet high
and two in diameter, but are usually less than thirty feet high. The
bark is used in tanning, and no use for the wood is reported, except
for fuel. White mangrove (_Laguncularia racemosa_), known also as
white buttonwood, is a Florida species. It attains a height of
thirty or forty feet and a diameter of a foot or more. It reaches
its largest size on the shores of Shark river, Florida. The wood is
dark yellow-brown, and the bark is rich in tannin, and the tree may
become valuable as a source of tanbark.
Near akin to white mangrove is Florida buttonwood (_Conocarpus
erecta_) which is highly esteemed as fuel. It burns slowly like
charcoal. Trees are from twenty to fifty feet high. Its range lies
in southern Florida. Black olive tree (_Terminalia buceras_) belongs
in the south Florida group, and the wood is exceedingly hard and
heavy. The trunk is often two or three feet in diameter, but lies on
the ground like a log, with upright stems growing from it. Tanners
make use of the bark.
[Illustration]
CABBAGE PALMETTO
[Illustration: CABBAGE PALMETTO]
THE PALMS
Lumbermen in this country could get along very well without the palms,
as they are little used for ordinary lumber. Their wood does not grow in
concentric rings, like that of the ordinary tree. The stems are usually
single, cylindrical, and unbranched. The fruit is berry-like, and is
usually one seeded, though sometimes there are two or three. When a seed
sprouts, it puts out at first a single leaf, like a grain of corn. About
130 genera of palms are recognized in the world, most of them in the
tropics, but several in the United States are of tree size. Botanists
divide the palms of the United States into two groups, the palm family
and the lily family. The yuccas belong in the lily family. In the very
brief treatment that can be given the subject here, it is not necessary
to recognize strict family divisions.
CABBAGE PALMETTO (_Sabal palmetto_) grows in the coast region from North
Carolina to southern Florida, and west to the Apalachicola river. It is
sometimes called Bank’s palmetto, cabbage tree, and tree palmetto. The
name cabbage is due to the large leaf-bud in the top of the stem which
is cooked as a substitute for cabbage. A sharp hatchet and some
experience are necessary to a successful operation in extracting the bud
from the tough fibers which surround it.
This palm is a familiar sight in the coast region within its range. The
tall trunks, with tufts of leaves at the tops, suggest the supposed
scenery of the Carboniferous age. Usually the trunks, in thick stands,
rise straight like columns from twenty to forty feet high, but
occasionally they bend in long, graceful curves, as if the weight of the
tops caused them to careen, which is probably what does happen. They
vary in diameter from eight inches to two feet.
The leaves are five or six feet long, and seven or eight wide, with
stems six or seven feet long. Flowers occur in racemes two feet or more
in length. The fruit is spherical and about a third of an inch in
diameter. The roots are an important part of this palm, and are adapted
to their environment, forming a rounded mass four or five feet in
diameter, while small rope-like roots, half an inch in diameter,
penetrate the wet marshy soil fifteen or twenty feet. The large,
globe-like mass gives support in the soft soil, and the stringy roots
supply water and mineral substances essential to growth. The wood is
light, soft, pale-brown, with numerous hard, fibro-vascular bundles, the
outer rim about two inches thick and much lighter and softer than the
interior. The most important use for the wood at present is as wharf
piles. It lasts well and is ideal in form. It is of historical interest
that Fort Moultrie which defended Charleston, South Carolina, in the
Revolutionary war, was built of palmetto logs. When the British made
their memorable attack in 1776, their cannon balls buried in the spongy
logs without dislodging them, and the fort successfully withstood the
bombardment of ten hours, and disabled nine of the ten British ships
taking part in the assault.
The wood is employed to a small extent in furniture making, and the bark
for scrubbing brushes. Some of the finest forests of palmetto in Florida
are much injured by fire that runs up the trunks to feed on stubs of
leaves.
SILKTOP PALMETTO (_Thrinax parviflora_) and silvertop palmetto (_Thrinax
microcarpa_) are species met with on some of the islands off the coast
of southern Florida.
MEXICAN PALMETTO (_Sabal mexicana_) is much like cabbage palmetto in
size and general appearance, and is put to similar uses, except that the
leaf-bud does not appear to be used as food. The tree occurs in Texas
along the lower Rio Grande, and southward into Mexico where the leaves
are employed as house thatch by improvident Mexicans and Indians who do
not care to exert themselves to procure better roofing material. In the
vicinity of Brownsville, Texas, trunks of this palm are employed as
porch posts and present a rustic appearance. They are said to last many
years. The average size of trunks in Texas is fifteen or twenty feet
high and a foot or less in diameter, but some much larger are found in
Mexico. Some of the wharfs along the Texas coast are built on palmetto
piles. It is said the trunks are not as strong as those of the cabbage
palmetto in Florida.
SARGENT PALM (_Pseudophœnix sargentii_) is interesting but not
commercially important, but may become so as an ornamental plant. It is
occasionally planted on lawns in south Florida. Leaves are five or six
feet long with stems still longer. The clusters of flowers are sometimes
three feet in length. A single species is known, occurring on certain
keys in southern Florida, and is so limited in its range that it would
be possible to count every tree in existence. A grove of 200 or 300
trees occurs on Key Largo.
ROYAL PALM (_Oreodoxa regia_) is one of the largest palms of this
country. It is said to reach a height of eighty feet, but such sizes are
rare. The trunk rises from an enlarged base, and may be two feet in
diameter. Bark is light gray in color, and its appearance suggests a
column of cement. Leaves are ten or twelve feet long, and the stems
increase the total length to twenty feet or more. Flowers are two feet
in length, and in Florida open in January and February. The fruit is
smaller than would be expected of a tree so large. It is a drupe about
the size of a half-grown grape. The wood is spongy, but the outer
portion of the stem is strong and is made into canes and other small
articles. Trunks are sometimes used as wharf piles. This palm’s range is
confined to south Florida in this country, but it is common in the West
Indies. In Miami and other towns of southern Florida it is much planted
for ornament.
FANLEAF PALM (_Neowashingtonia filamentosa_) also called Washington
palm, California fan palm, Arizona palm, and wild date, ranges through
southern California, and occupies depressions in the desert west of the
Colorado river. There are said to be several forms and varieties. It
ranges in height from thirty-five to seventy feet and in diameter from
twenty to thirty inches. Trunks are of nearly the same diameter from
bottom to top, or taper very gradually. They usually lean a little. Dead
leaves hang about the trunks and blaze quickly when fire touches them,
but the palm is seldom killed by fire. The small black fruit is about a
third of an inch in diameter, and of no commercial importance; wood is
little used; and the tree is chiefly ornamental, and has been much
planted in California.
MOHAVE YUCCA (_Yucca mohavensis_) is one of a half dozen or more palms
of the yucca genus and the lily family. Trees of this group are
characterized by their stiff, sharp-pointed leaves, some of which are
called daggers and others bayonets. Both names are appropriate. The
Mohave yucca takes its name from the Mohave desert in California, where
it is occasionally an important feature of the doleful landscape. The
ragged, leather-like leaves, forming the tops of the short, weird trees,
rattle in the wind, or resound with the patter of pebbles when
sandstorms sweep across the dry wastes. It is believed to be one of the
most slowly-growing trees of this country. Trunks are seldom more than
fifteen feet high and eight or ten inches in diameter. The wood is
spongy and interlaced with tough, stringy fibers. Stockmen whose ranges
include this tree, make corrals of the stems by setting them in the
ground as palisades. When weathered by wind and made bone dry by the
sun’s fierce heat, the trunks are reduced to almost cork-lightness.
Other yuccas are the Spanish bayonet (_Yucca treculeana_) of Texas;
Joshua-tree (_Yucca arborescens_), which ranges from Utah to California
and is known as tree yucca, yucca cactus, and the Joshua; Schott yucca
(_Yucca brevifolia_) of southern Arizona; broadfruit yucca (_Yucca
macrocarpa_) of southwestern Texas; aloe-leaf yucca (_Yucca aloifolia_)
with a range from North Carolina near the coast to Louisiana; and
Spanish dagger (_Yucca gloriosa_), on the coast and islands of South
Carolina.
GIANT CACTUS (_Cereus giganteus_) is a leafless tree of Arizona and
attains a height of forty or sixty feet, diameter of one or two.
About twenty genera of cactus are known in the world and a large
number of species. Two genera, the cereuses and opuntias, have
representatives of tree size in this country. The two genera differ
in form. Cereus in the Latin language means a candle, and the
cactuses of that genus stand up in straight stems like candles, or
have branches like old-fashioned candlesticks. The opuntias have
flat, jointed stems, like thick leaves. Giant cactus bears flowers
four inches long and two wide; fruit two inches long and one wide,
and edible. Indians derive a considerable part of their food from
this cactus. They use the wood for rafters, fences, fuel, lances,
and bows. The trunks consist of bundles of fiber, very hard and
strong. In the dry region where this cactus grows, the woody parts
of fallen stems last long periods, some say for centuries, but there
are no records. Schott cactus (_Cereus schottii_) and Thurber cactus
(_Cereus thurberi_) are found in southern Arizona and southward in
Mexico.