themselves the most conspicuous and remarkable feature of the
tropical forests is the profusion of woody creepers and climbers
that everywhere meet the eye. They twist around the slenderer stems,
they drop down pendent from the branches, they stretch tightly
from tree to tree, they hang looped in huge festoons from bough to
bough, they twist in great serpentine coils or lie in entangled
masses on the ground. Some are slender, smooth, and root-like;
others are rugged or knotted; often they are twined together into
veritable cables; some are flat like ribands, others are curiously
waved and indented. Where they spring from or how they grow is at
first a complete puzzle. They pass overhead from tree to tree, they
stretch in tight cordage like the rigging of a ship from the top
of one tree to the base of another, and the upper regions of the
forest often seem full of them without our being able to detect
any earth-growing stem from which they arise. The conclusion is at
length forced upon us that these woody climbers must possess the
two qualities of very long life and almost indefinite longitudinal
growth, for by these suppositions alone can we explain their
characteristic features. The growth of climbers, even more than
all other plants, is upward towards the light. In the shade of the
forest they rarely or never flower, and seldom even produce foliage;
but when they have reached the summit of the tree that supports
them, they expand under the genial influence of light and air, and
often cover their foster-parent with blossoms not its own. Here,
as a rule, the climber’s growth would cease; but the time comes
when the supporting tree rots and falls, and the creeper comes
with it in torn and tangled masses to the ground. But though its
foster-parent is dead it has itself received no permanent injury,
but shoots out again till it finds a fresh support, mounts another
tree, and again puts forth its leaves and flowers. In time the old
tree rots entirely away and the creeper remains tangled on the
ground. Sometimes branches only fall and carry a portion of the
creeper tightly stretched to an adjoining tree; at other times the
whole tree is arrested by a neighbour to which the creeper soon
transfers itself in order to reach the upper light. When by the
fall of a branch the creepers are left hanging in the air, they
may be blown about by the wind and catch hold of trees growing up
beneath them, and thus become festooned from one tree to another.
When these accidents and changes have been again and again repeated
the climber may have travelled very far from its parent stem,
and may have mounted to the tree tops and descended again to the
earth several times over. Only in this way does it seem possible
to explain the wonderfully complex manner in which these climbing
plants wander up and down the forest as if guided by the strangest
caprices, or how they become so crossed and tangled together in
the wildest confusion.
The variety in the length, thickness, strength and toughness of
these climbers, enables the natives of tropical countries to put
them to various uses. Almost every kind of cordage is supplied by
them. Some will stand in water without rotting, and are used for
cables, for lines to which are attached fish-traps, and to bind and
strengthen the wooden anchors used generally in the East. Boats and
even large sailing vessels are built, whose planks are entirely
fastened together by this kind of cordage skilfully applied to
internal ribs. For the better kinds of houses, smooth and uniform
varieties are chosen, so that the beams and rafters can be bound
together with neatness, strength and uniformity, as is especially
observable among the indigenes of the Amazonian forests. When
baskets of great strength are required special kinds of creepers
are used; and to serve almost every purpose for which we should
need a rope or a chain, the tropical savage adopts some one of
the numerous forest-ropes which long experience has shown to have
qualities best adapted for it. Some are smooth and supple; some
are tough and will bear twisting or tying; some will last longest
in salt water, others in fresh; one is uninjured by the heat and
smoke of fires, while another is bitter or otherwise prejudicial
to insect enemies.
Besides these various kinds of trees and climbers which form the
great mass of the equatorial forests and determine their general
aspect, there are a number of forms of plants which are always more
or less present, though in some parts scarce and in others in great
profusion, and which largely aid in giving a special character to
tropical as distinguished from temperate vegetation. Such are the
various groups of palms, ferns, ginger-worts, and wild plantains,
arums, orchids, and bamboos; and under these heads we shall give a
short account of the part they take in giving a distinctive aspect
to the equatorial forests.
_Palms._--Although these are found throughout the tropics and a few
species even extend into the warmer parts of the temperate regions,
they are yet so much more abundant and varied within the limits of
the region we are discussing that they may be considered as among
the most characteristic forms of vegetation of the equatorial zone.
They are, however, by no means generally present, and we may pass
through miles of forest without even seeing a palm. In other parts
they abound; either forming a lower growth in the lofty forest, or
in swamps and on hill-sides sometimes rising up above the other
trees. On river-banks they are especially conspicuous and elegant,
bending gracefully over the stream, their fine foliage waving in
the breeze, and their stems often draped with hanging creepers.
The chief feature of the palm tribe consists in the cylindrical trunk
crowned by a mass of large and somewhat rigid leaves. They vary in
height from a few feet to that of the loftiest forest-trees. Some
are stemless, consisting only of a spreading crown of large pinnate
leaves; but the great majority have a trunk slender in proportion to
its height. Some of the smaller species have stems no thicker than
a lead pencil, and four or five feet high; while the great Mauritia
of the Amazon has a trunk full two feet in diameter, and more than
100 feet high. Some species probably reach a height of 200 feet,
for Humboldt states that in South America he measured a palm, which
was 192 English feet high. The leaves of palms are often of immense
size. Those of the _Manicaria saccifera_ of Para are thirty feet
long and four or five feet wide, and are not pinnate but entire and
very rigid. Some of the pinnate leaves are much larger, those of the
_Raphia tædigera_ and _Maximiliana regia_ being both sometimes more
than fifty feet long. The fan-shaped leaves of other species are
ten or twelve feet in diameter. The trunks of palms are sometimes
smooth and more or less regularly ringed, but they are frequently
armed with dense prickles which are sometimes eight inches long. In
some species, the leaves fall to the ground as they decay leaving a
clean scar, but in most cases they are persistent, rotting slowly
away, and leaving a mass of fibrous stumps attached to the upper
part of the stem. This rotting mass forms an excellent soil for
ferns, orchids, and other semi-parasitical plants, which form an
attractive feature on what would otherwise be an unsightly object.
The sheathing margins of the leaves often break up into a fibrous
material, sometimes resembling a coarse cloth, and in other cases
more like horsehair. The flowers are not individually large, but
form large spikes or racemes, and the fruits are often beautifully
scaled and hang in huge bunches which are sometimes more than a load
for a strong man. The climbing palms are very remarkable, their
tough, slender, prickly stems mounting up by means of the hooked
midribs of the leaves to the tops of the loftiest forest-trees,
above which they send up an elegant spike of foliage and flowers.
The most important are the American _Desmoncus_ and the Eastern
_Calamus_, the latter being the well-known rattan or cane of which
chair-seats are made, from the Malay name “rotang.” The rattan-palms
are the largest and most remarkable of the climbing group. They
are very abundant in the drier equatorial forests, and more than
sixty species are known from the Malay Archipelago. The stems (when
cleaned from the sheathing leaves and prickles) vary in size from
the thickness of a quill to that of the wrist; and where abundant
they render the forest almost impassable. They lie about the ground
coiled and twisted and looped in the most fantastic manner. They
hang in festoons from trees and branches, they rise suddenly through
mid air up to the top of the forest, or coil loosely over shrubs
and in thickets like endless serpents. They must attain an immense
age, and apparently have almost unlimited powers of growth, for some
are said to have been found which were 600 or even 1000 feet long,
and if so, they are probably the longest of all vegetable growths.
The mode in which such great lengths and tangled convolutions have
been attained has already been explained in the general account of
woody climbers. From the immense strength of these canes and the
facility with which they can be split, they are universally used
for cordage in the countries where they grow in preference to any
other climbers, and immense quantities are annually exported to
all parts of the world.
_Uses of Palm-trees and their Products._--To the natives of the
equatorial zone the uses of palms are both great and various. The
fruits of several species--more especially the cocoa-nut of the
East and the peach-nut (_Guilielma speciosa_) of America--furnish
abundance of wholesome food, and the whole of the trunk of the
sago-palm is converted into an edible starch--our sago. Many
other palm-fruits yield a thin pulp, too small in quantity to be
directly eaten, but which when rubbed off and mixed with a proper
quantity of water forms an exceedingly nutritious and agreeable
article of food. The most celebrated of these is the assai of the
Amazon, made from the fruit of _Euterpe oleracea_, and which, as
a refreshing, nourishing, and slightly stimulating beverage for a
tropical country, takes the place of our chocolate and coffee. A
number of other palms yield a similar product, and many that are
not eaten by man are greedily devoured by a variety of animals, so
that the amount of food produced by this tribe of plants is much
larger than is generally supposed.
The sap which pours out of the cut flower-stalk of several species
of palm when slightly fermented forms palm-wine or toddy, a very
agreeable drink; and when mixed with various bitter herbs or roots
which check fermentation, a fair imitation of beer is produced.
If the same fluid is at once boiled and evaporated it produces a
quantity of excellent sugar. The _Arenga saccharifera_, or sugar-palm
of the Malay countries, is perhaps the most productive of sugar. A
single tree will continue to pour out several quarts of sap daily
for weeks together, and where the trees are abundant this forms
the chief drink and most esteemed luxury of the natives. A Dutch
chemist, Mr. De Vry, who has studied the subject in Java, believes
that great advantages would accrue from the cultivation of this
tree in place of the sugar-cane. According to his experiments it
would produce an equal quantity of sugar of good quality with
far less labour and expense, because no manure and no cultivation
would be required, and the land will never be impoverished as it
so rapidly becomes by the growth of sugar-cane. The reason of this
difference is, that the whole produce of a cane-field is taken
off the ground, the crushed canes being burnt; and the soil thus
becomes exhausted of the various salts and minerals which form
part of the woody fibre and foliage. These must be restored by
the application of manure, and this, together with the planting,
weeding, and necessary cultivation, is very expensive. With the
sugar-palm, however, nothing whatever is taken away but the juice
itself; the foliage falls on the ground and rots, giving back to
it what it had taken; and the water and sugar in the juice being
almost wholly derived from the carbonic acid and aqueous vapour of
the atmosphere, there is no impoverishment; and a plantation of
these palms may be kept up on the same ground for an indefinite
period. Another most important consideration is, that these trees
will grow on poor rocky soil and on the steep slopes of ravines and
hill-sides where any ordinary cultivation is impossible, and a great
extent of fertile land would thus be set free for other purposes.
Yet further, the labour required for such sugar plantations as
these would be of a light and intermittent kind, exactly suited to
a semi-civilized people to whom severe and long-continued labour is
never congenial. This combination of advantages appears to be so
great, that it seems possible that the sugar of the world may in
the future be produced from what would otherwise be almost waste
ground; and it is to be hoped that the experiment will soon be tried
in some of our tropical colonies, more especially as an Indian
palm, _Phœnix sylvestris_, also produces abundance of sugar, and
might be tried in its native country.
Other articles of food produced from palms are, cooking-oil from the
cocoa-nut and baccaba palm, salt from the fruit of a South American
palm (_Leopoldinia major_), while the terminal bud or “cabbage” of
many species is an excellent and nutritious vegetable; so that palms
supply bread, oil, sugar, salt, fruit, and vegetables. Oils for
various other purposes are made from several distinct palms, while
wax is secreted from the leaves of some South American species; the
resin called dragon’s-blood is the product of one of the rattan
palms; while the fruit of the Areca palm is the “betel-nut” so
universally chewed by the Malays as a gentle stimulant, and which
is their substitute for the opium of the Chinese, the tobacco of
Europeans, and the coca-leaf of South America.
For thatching, the leaves of palms are invaluable, and are
universally used wherever they are abundant; and the petioles
or leaf-stalks, often fifteen or twenty feet long, are used as
rafters, or when fastened together with pegs form doors, shutters,
partitions, or even the walls of entire houses. They are wonderfully
light and strong, being formed of a dense pith covered with a hard
rind or bark, and when split up and pegged together serve to make
many kinds of boxes, which, when covered with the broad leaves of
a species of screw-pine and painted or stained of various colours,
are very strong and serviceable as well as very ornamental. Ropes
and cables are woven from the black fibrous matter that fringes the
leaves of the sugar-palm and some other species, while fine string
of excellent quality used even for bow-strings, fishing-lines, and
hammocks, is made of fibres obtained from the unopened leaves of
some American species. The fibrous sheath at the base of the leaves
of the cocoa-nut palm is so compact and cloth-like, that it is used
for a variety of purposes, as for strainers, for wrappers, and to
make very good hats. The great woody spathes of the larger palms
serve as natural baskets, as cradles, or even as cooking-vessels
in which water may be safely boiled. The trunks form excellent
posts and fencing, and when split make good flooring. Some species
are used for bows, others for blow-pipes; the smaller species are
sometimes used as needles or to make fish-hooks, and the larger
as arrows. To describe in detail all the uses to which palm-trees
and their products are applied in various parts of the world might
occupy a volume; but the preceding sketch will serve to give an idea
of how important a part is filled by this noble family of plants,
whether we regard them as a portion of the beautiful vegetation of
the tropics, or in relation to the manners and customs, the lives
and the well-being of the indigenous inhabitants.
_Ferns._--The type of plants which, next to palms, most attracts
attention in the equatorial zone, is perhaps that of the ferns,
which here display themselves in vast profusion and variety. They
grow abundantly on rocks and on decaying trees; they clothe the
sides of ravines and the margins of streams; they climb up the
trees and over bushes; they form tufts and hanging festoons among
the highest branches. Some are as small as mosses, others have huge
fronds eight or ten feet long, while in mountainous districts the
most elegant of the group, the tree-ferns, bear their graceful
crowns on slender stems twenty to thirty, or even fifty feet high.
It is this immense variety rather than any special features that
characterises the fern-vegetation of the tropics. We have here
almost every conceivable modification of size, form of fronds,
position of spores, and habit of growth, in plants that still
remain unmistakably ferns. Many climb over shrubs and bushes in
a most elegant manner; others cling closely to the bark of trees
like ivy. The great birds’-nest fern (_Platycerium_) attaches its
shell-like fronds high up on the trunks of lofty trees. Many small
terrestrial species have digitate, or ovate, or ivy-shaped, or even
whorled fronds, resembling at first sight those of some herbaceous
flowering-plants. Their numbers may be judged from the fact that in
the vicinity of Tarrapoto, in Peru, Dr. Spruce gathered 250 species
of ferns, while the single volcanic mountain of Pangerango in Java
(10,000 feet high) is said to have produced 300 species.
_Ginger-worts and wild Bananas._--These plants, forming the families
Zingiberaceæ and Musaceæ of botanists, are very conspicuous ornaments
of the equatorial forests, on account of their large size, fine
foliage, and handsome flowers. The bananas and plantains are well
known as among the most luxuriant and beautiful productions of the
tropics. Many species occur wild in the forests; all have majestic
foliage and handsome flowers, while some produce edible fruit. Of
the ginger-worts (Zingiberaceæ and Marantaceæ), the well-known
cannas of our tropical gardens may be taken as representatives, but
the equatorial species are very numerous and varied, often forming
dense thickets in damp places, and adorning the forest shades with
their elegant and curious or showy flowers. The maranths produce
“arrow-root,” while the ginger-worts are highly aromatic, producing
ginger, cardamums, grains of paradise, turmeric and several medicinal
drugs. The Musaceæ produce the most valuable of tropical fruits
and foods. The banana is the variety which is always eaten as a
fruit, having a delicate aromatic flavour; the plantain is a larger
variety which is best cooked. Roasted in the green state it is an
excellent vegetable resembling roasted chestnuts; when ripe it is
sometimes pulped and boiled with water, making a very agreeable
sweet soup; or it is roasted, or cut into slices and fried, in
either form being a delicious tropical substitute for fruit pudding.
These plants are annuals, producing one immense bunch of fruit.
This bunch is sometimes four or five feet long containing near 200
plantains, and often weighs about a hundredweight. They grow very
close together, and Humboldt calculated that an acre of plantains
would supply more food than could be obtained from the same extent
of ground by any other known plant. Well may it be said that the
plantain is the glory of the tropics, and well was the species
named by Linnæus--_Musa paradisiaca_!
_Arums._--Another very characteristic and remarkable group of
tropical plants are the epiphytal and climbing arums. These are
known by their large, arrow-shaped, dark green and glossy leaves,
often curiously lobed or incised, and sometimes reticulated with
large open spaces, as if pieces had been regularly eaten out of them
by some voracious insects. Sometimes they form clusters of foliage
on living or dead trees to which they cling by their aerial roots.
Others climb up the smooth bark of large trees, sending out roots
as they ascend which clasp around the trunk. Some mount straight up,
others wind round the supporting trunks, and their large, handsome,
and often highly-remarkable leaves, which spread out profusely
all along the stem, render them one of the most striking forms of
vegetation which adorn the damper and more luxuriant parts of the
tropical forests of both hemispheres.
_Screw-pines._--These singular plants, constituting the family
Pandanaceæ of botanists, are very abundant in many parts of the
Eastern tropics, while they are comparatively scarce in America.
They somewhat resemble Yuccas, but have larger leaves which grow in
a close spiral screw on the stem. Some are large and palm-like, and
it is a curious sight to stand under these and look up at the huge
vegetable screw formed by the bases of the long drooping leaves.
Some have slender-branched trunks, which send out aerial roots;
others are stemless, consisting of an immense spiral cluster of
stiff leaves ten or twelve feet long and only two or three inches
wide. They abound most in sandy islands, while the larger species
grow in swampy forests. Their large-clustered fruits, something like
pineapples, are often of a red colour; and their long stiff leaves
are of great use for covering boxes and for many other domestic
uses.
_Orchids._--These interesting plants, so well known from the ardour
with which they are cultivated on account of their beautiful and
singular flowers, are pre-eminently tropical, and are probably more
abundant in the mountains of the equatorial zone than in any other
region. Here they are almost omnipresent in some of their countless
forms. They grow on the stems, in the forks or on the branches of
trees; they abound on fallen trunks; they spread over rocks, or
hang down the face of precipices; while some, like our northern
species, grow on the ground among grass and herbage. Some trees
whose bark is especially well adapted for their support are crowded
with them, and these form natural orchid-gardens. Some orchids
are particularly fond of the decaying leaf-stalks of palms or of
tree-ferns. Some grow best over water, others must be elevated on
lofty trees and well exposed to sun and air. The wonderful variety
in the form, structure, and colour of the flowers of orchids is
well known; but even our finest collections give an inadequate idea
of the numbers of these plants that exist in the tropics, because
a large proportion of them have quite inconspicuous flowers and
are not worth cultivation. More than thirty years ago the number
of known orchids was estimated by Dr. Lindley at 3,000 species,
and it is not improbable that they may be now nearly doubled. But
whatever may be the numbers of the collected and described orchids,
those that still remain to be discovered must be enormous. Unlike
ferns, the species have a very limited range, and it would require
the systematic work of a good botanical collector during several
years to exhaust any productive district--say such an island as
Java--of its orchids. It is not therefore at all improbable that
this remarkable group may ultimately prove to be the most numerous
in species of all the families of flowering plants.
Although there is a peculiarity of habit that enables one soon to
detect an orchidaceous plant even when not in flower, yet they vary
greatly in size and aspect. Some of the small creeping species
are hardly larger than mosses, while the large Grammatophyllums
of Borneo, which grow in the forks of trees, form a mass of leafy
stems ten feet long, and some of the terrestrial species--as the
American Sobralias--grow erect to an equal height. The fleshy
aerial roots of most species give them a very peculiar aspect, as
they often grow to a great length in the open air, spread over the
surface of rocks, or attach themselves loosely to the bark of trees,
extracting nourishment from the rain and from the aqueous vapour of
the atmosphere. Yet notwithstanding the abundance and variety of
orchids in the equatorial forests they seldom produce much effect
by their flowers. This is due partly to the very large proportion
of the species having quite inconspicuous flowers; and partly to
the fact that the flowering season for each kind lasts but a few
weeks, while different species flower almost every month in the
year. It is also due to the manner of growth of orchids, generally
in single plants or clumps which are seldom large or conspicuous
as compared with the great mass of vegetation around them. It is
only at long intervals that the traveller meets with anything
which recalls the splendour of our orchid-houses and flower-shows.
The slender-stalked golden Oncidiums of the flooded forests of
the Upper Amazon; the grand Cattleyas of the drier forests; the
Cœlogynes of the swamps, and the remarkable _Vanda lowii_ of the
hill forests of Borneo, are the chief examples of orchid-beauty
that have impressed themselves on the memory of the present writer
during twelve years’ wandering in tropical forests. The last-named
plant is unique among orchids, its comparatively small cluster of
leaves sending out numerous flower-stems, which hang down like
cords to a length of eight feet, and are covered with numbers of
large star-like crimson-spotted flowers.