Personality of plants — Royal Dixon

PERSONALITY OF PLANTS

The Fuchsia has a Distinctive and Esthetic Manner.

PERSONALITY
OF PLANTS

By ROYAL DIXON and
FRANKLYN E. FITCH

New York
BOULLION-BIGGS
1923

PRINTED IN U. S. A.

Page

INTRODUCTION 11

ORIGIN OF PLANTS 17

LIFE OF A PLANT 27

MIGRATIONS OF PLANTS 39

COMRADES OF THE PLANT WORLD 57

ALLIES OF THE PLANT WORLD 69

MARRIAGE CUSTOMS OF PLANTS 83

ART IN THE PLANT WORLD 95

MUSIC IN THE PLANT WORLD 110

SCIENCE IN THE PLANT WORLD 122

RELIGION IN THE PLANT WORLD 141

PLANT MYTHOLOGY 154

MYSTICISM IN THE PLANT WORLD 167

PLANT INTELLIGENCE 186

THE HIGHER LIFE OF PLANTS 204

PLANTS & MEN 215

EDWIN MARKHAM

and

ANNA CATHERINE MARKHAM

who live their poetry.

“That nothing walks with aimless feet;
That not one life shall be destroyed;
Or cast as rubbish to the void,
When God hath made the pile complete;

“That not one worm is cloven in vain;
That not a moth with vain desire
Is shrivel’d in a fruitless fire,
Or but subserves another’s gain.”

--Tennyson.

INTRODUCTION

“The natural world, so to speak, is the raw material of the spiritual. Therefore, ere man can understand the spiritual, he must understand the natural,” writes Thomas Gentry.

The authors of this book would go a step further and say that the natural world is the spiritual. Soul and body, ephemeral and material, on this plane of existence are ineffably bound together. If you would climb to sublime heights of ghostly exaltation, study first the grass at your feet. If you would unravel the mysteries of the universe, desert the cloistered hearth for the wonders of woods and meadows. Slow-thinking man will never understand the secret of his own existence, until he thoroughly understands the plants outside his window.

For one to examine dead, withered specimens and hope to understand Nature is as if a person should analyze hundreds of Egyptian mummies in order to acquaint himself with the human race. You must seek the flowers on their native heath and treat them as friends and equals. Too often is the human creature inclined to look upon members of the vegetable kingdom as things apart from the world of life--insensate beings which can be cut down and trampled without offense--mere “growths,” more akin to earth and stone than to himself.

As a matter of fact, among the many forms of matter which exist on this earth of ours, the only clear-cut division is between the organic and the inorganic. The primary characteristic which distinguishes a living creature from inanimate objects about it is, in the words of Arthur Dendy, its power of “reacting toward its environment in such a manner as to conduce to its own well-being; of controlling not only its own behaviour but also the behaviour alike of its fellow creatures and of inanimate objects, in its own interests, thereby maintaining its own position in the universal struggle for existence.”

If this, then, is the one characteristic which distinguishes all terrestrial life, it follows that all creatures from the unicellular protoza to man himself are intimately related, are all part and parcel of the same system, are recognizable by differences in degree but not in kind, and are all interesting manifestations of that mysterious thing we call life. No creature lives or dies to itself. The correlation of organisms in Nature is similiar to the correlation of organs in individual plants and animals.

If the reader will but face this fact, he will approach the study of Nature with a new reverence. He will recognize the oneness and kinship of all life.

It is largely the object of this book to explore the inner recesses of breathing and thinking plantdom--to take the reader beyond the limits of text-book botany into regions of sympathetic insight--to show how even human arts and sciences are unchangeably bound up with the lives and hopes of the grasses and flowers.

To do this comprehensively, it has been thought wise not only to indicate how plants think and act but to incorporate a broad general history of their race stretching back to their first appearance on the planet and carried forward to the Burbank creations. With this knowledge in hand, we are better equipped to approach that fascinating realm which touches on the intelligence, the spirituality, the mysticism, the psychic phenomena, the higher life of plants.

In all this, the manifest independence of plant life and purpose is convincingly apparent. The plants have their own lives to lead and their own evolutionary processes to carry on. They completed the conquest of the earth long before the first human being appeared on its surface. Out of approximately a hundred thousand species of flowering plants, it has been estimated that only two hundred and forty-seven render direct and important service to man, and of these, only about fifty-four are utilized by him to any great extent.

While today it is no longer the fashion to believe that plants were created for man’s sole benefit, yet it cannot be denied that, because of their physical limitations and inferior intelligence, the plants frequently become very docile servants of the human race, thereby thriving mightily and to their own great advantage. This is as it should be. It is a law of earthly life. The danger lies in the contempt which this servitude engenders in the consciousness of man, the master. The plants are inferiors but very wonderful inferiors. We should accord them the highest respect. We should accept our dominion over them as a favour of a beneficent Providence,--a priceless gift which it is criminal to squander or misuse.

CHAPTER I

Origin of Plants

“_’Tis a quaint thought, and yet perchance,
Sweet blossoms, ye have sprung
From flowers that over Eden once
Their pristine fragrance flung._”

“In the beginning God created the heaven and earth. And the earth was without form and void; and darkness was upon the face of the deep. And the spirit of God moved upon the face of the waters. And God said, Let there be light: and there was light!”

There is no greater mystery than the mystery of creation. Nowhere is its story told more eloquently and more scientifically than in the opening words of Genesis. All the fruitage of centuries of research but reaffirms this ancient narrative.

In the early days of this planet, when its crust was scarcely hardened from the molten state, there reigned what might be called the age of water. The entire surface of the globe was covered with a sea of restless, moving liquid, overcharged with a heavy atmosphere of vapour, so dense that not a single ray of light could penetrate it. As the process of cooling went on, more and more moisture condensed out of the air, until finally the first ray of light reached the universal sea and terrestrial day began.

Here in this dim, watery world, about the time that the first land began to emerge from the deep, by some divine, mysterious agency, the first life was born.

No doubt it was one-celled, free-moving, and like modern Flagellates, partaking of the nature of both plant and animal.

Slowly, and in response to evolutionary promptings, simple aquatic plant forms began to develop from the primary single cells. Animal life may have begun a simultaneous development, but if it did, it did not become strong enough to make any impress on the geologic rock from which we draw our data.

Certainly the plants were in the ascendency. The mobile green Algae were characteristic of the time. It is a remarkable thing that though they are probably the progenitors of all that vast world of vegetable life which enriches the world today, the Algae have always gone on reproducing their own kind. Today we can watch, under a microscope, the activities of the first form of terrestrial life, born incalculable aeons ago.

Mayhap the earth would be peopled exclusively by Algae and similar forms today, if it had not been for a prehistoric accident. One day, the water suddenly receded from a bit of land and left some Algae in the mud behind it. Now, the Algae had always been used to plenty of water and they saw that unless they did some quick thinking, they were in danger of drying up and blowing away. Accordingly, by common consent, they secreted and surrounded themselves with a jelly-like mass capable of absorbing and holding water. The amphibious Liverworts and the Ricciocarpus Natans do the same thing today.

With the Algae successfully living in the mud, surrounded by their mucilaginous water-reservoirs, it was but a step for some enterprising individual to extend a portion of his own tissue in search of more water. By this simple act, the first root came into being, and lo! there were terrestrial plants.

It is to be noted that all development in the plant world is born of necessity. To the plants, dependence upon water, food and the impulse to reproduction may be ascribed the start of many a new form among them. In the more complex groups we seem to see a conscious striving for higher and better things, but the lowlier species often need the goad of circumstance to force them to attainment.

When the plants first emerged upon the land, a number of structural changes became necessary. Whereas in the marine world, water is absorbed directly by all parts of the plant, in land life special organs of absorption and conductivity must be developed. At first, the roots were mere rhizoids or hairs, aided by water-drinking leaves and tubers, as in the Mosses and Liverworts today; but it was not long before true root and vascular systems were evolved. Other changes which came with terrestrial life were greater rigidity of tissue and devices to guard against evaporation. Leaves were developed for the purposes of manufacturing starch by photosynthesis, spreading out into thin layers in order to present the greatest possible surface.

These lower land plants retained and still retain some characteristics of their aquatic ancestry, notably swimming spore cells, as in the Mosses. The formation of rigid cellulose about vegetable cells stops their movement, except when cilia or projections of protoplasm extend through openings in the cell walls. The Liverworts were probably among the first real land plants: their spores are non-motile and they have a massive, foot-like organ for the absorption of water.

To the liberality of Nature we must ascribe the development of the law which ties the plants to the soil. They started out as animals, but enjoyed such an abundance of food that it became unnecessary for them to go in search for it. Water and carbon dioxide, which formed their principal means of subsistence, were all about them; they settled down to a life of quiet ease. When Corals, Sponges, Oysters and other lower animals are similarly situated, they become as firmly rooted as any plant. Moreover, they have free-swimming larvae analogous to the active zoospores of certain members of the plant world.

The first land vegetation of the globe must have presented a curious spectacle. Imagine a forest consisting of endless repetitions of Algae, Fungi, Lichens, Liverworts and Mosses, with many forms of gigantic sizes. The fresh-water Algae early developed a clever device to save their race from extinction by drought. Certain cells in each plant became hard and devoid of water, presenting that phenomenon of suspended animation to be observed in many of the higher seeds. When drought overtook any particular plant, it died, but these special restive cells lived, and were carried about by the wind or other agencies until a new abundance of moisture called them out of their trance. As zygotes, they exist in the Nostoc today.

The first plants were non-sexual and propagated by cell division. They were therefore capable of little advancement. With the introduction of the sex element, infinite possibilities for racial improvement and differentiation were opened up. The Mosses and Ferns belonging to the family Archegoniatae early established an alternation of generation in which the spores give rise to a small plant which looks like a Liverwort and bears the reproductive organs. The fertilized ovum of this plant grows into a leafy, sexless individual which produces spores non-sexually. We therefore have a generation endowed with sex organs making for development and progress, alternating with a sexless generation calculated to continue the tendencies of the race.

It is undoubtedly the sex element which accounts for those “sports” or mutations in plantdom which occasionally overstep the limits of species to form new species.

In the luxurious atmosphere of the early globe, vegetation waxed strong and vigorous and attained remarkable proportions. The primeval woods served to draw the superabundant carbon from the air and in millions of decayed bodies store it up as graphite, coal, petroleum and illuminating gas. The present day graphite beds alone represent vast quantities of ancient vegetation. It is a unique experience to be able to write or draw pictures of these prehistoric plants and use, in the carbon of our pencils, portions of their very bodies.

Everything was on a grand scale in the “Old Red Sandstone” age. There were no real trees yet, but the Asterophyllites, with their tall, slender stems, looked much like Palms. The Eryptogams were immense Mushrooms. Algae, Zostera and Psilophytons covered the shores with a tangle of seaweed vegetation.

In the succeeding carboniferous period, the plant world reached the climax of its dominion. While the variety was still very much limited, its vigor and luxuriance were astounding. The Tree-ferns seem to have come down to us unchanged from that time, but other plant descendants have dwindled in size greatly. Our humble Mares’ Tails were then twenty or thirty foot trees called Calamites. The Club-Mosses were giant Lepidodendrons. Other immense plants which have no direct descendants were the Sigillarias and the Lomatophylos. With its flexible, fluted and checkered stems, saw-edged leaves, and hanging garlands of parasitic Ferns, the carboniferous forest presented a remarkable scene.

The air was still very moist, covering the entire earth with a permanent fog and a uniform temperature. It is said that certain present-day islands in the Pacific Ocean approximate these ancient conditions.

All the plants of that time were flowerless, and belonged to neither the monocotyledonous nor the dicotyledonous classes, which include the greater number of families today. Thanks to many excellent specimens found in coal mines, it is possible for scientists to classify as many as five hundred families. It is believed that coal itself was mostly formed from small plants, but often entire trunks of the tree-like forms are found in bituminous strata. Bits of bark, cones and petrified leaves have also been unearthed at different times.

In the course of evolution, the Conifer trees were the next to develop extensively. They gained a great ascendency, but were succeeded by Palms, Alders, Cypress and Elms. By the Miocene period, all the forms known in tropic Africa today had come into existence, but were restricted by no such regional limitations as they labour under now. Oaks and Palms, Birches and Bamboos, Elms and Laurels grew side by side. The Palms reached as far north as Bohemia, Switzerland and Belgium. Maples, Lindens, Planes, Spruces, Magnolias, Persimmons and Pines flourished in Greenland. The Silver Fir and the Southern Cypress advanced to within two hundred leagues of the North Pole. The California Redwoods and Sequoias are survivors of a race which flourished in this age.

Man came very late in the earth’s evolution, but he has had a profound effect upon the plant world. His most noteworthy feat has been to take comparatively weak plants like the grains and, for his own purposes, give them large areas in which to grow. Wheat, Maize, Yams and Tobacco became widely diffused as cultivated plants before the historic era. It is probable that Rice and the Legumes were first domesticated in Asia; Barley and Wheat in Egypt; and Maize, Potatoes, Yams and Manioc in America.

The origin and development of plants is a fascinating study. So authentic are the records which they have left in the eternal rocks that we have little difficulty in reconstructing their entire race history.

THE LIFE OF A DAISY IS SPENT IN BRIGHTENING OUR FIELDS AND PASTURES

CHAPTER II

LIFE OF A PLANT

“We cannot pass a blade of grass unheeded by the way, For it whispers to our thoughts and we its silent voice obey.”

--J. E. Carpenter

The growth and development of a plant, though such a common thing, is full of very real wonder and mystery. It takes only a little observation to discover the various stages in the process, but how they are brought about and by what laws they are governed, not even the most astute investigators can always say.

To the lay mind, the statement that the plants depend upon the soil for their nourishment is quite self-evident, yet it is extremely inaccurate. It is now quite certain that the vegetable world relies upon the air for its largest and most important food supply. The great mass of carbon which is the chief constituent of all plant structure is drawn almost exclusively from the atmosphere. While it is true that many vital elements are obtained from the earth, all green plants manufacture the greater part of their solid material out of the carbon dioxide of the air. Of what the plants do obtain from the soil, water makes up the largest bulk. The bread and meat of the plant world is carbon dioxide; the drink is soil water in which is dissolved certain essential salts and condiments.

A chemical analysis of a Green Pea will show approximately 46.5% of carbon, 4.2% of nitrogen and 3.1% of all other elements, exclusive of the hydrogen and oxygen which make up the water permeating all tissue.

This is truly a startling fact. Instead of belonging to the earth, the plants then belong primarily to the air. The air is their natural habitat; the earth serves to give them a fixed place in the world and provide them with flavoured water to drink.

Plants are born from seeds, the joint product of two previous individuals; they live by eating and drinking; they marry and in turn rear families of their own. It is our purpose in this chapter to show, in a very definite way, that this is not mere figurative language but a common-sense statement of fact.

The cycle of plant life can be illustrated by any dicotyledonous, herbaceous annual. If one is so inclined he may hark back to his high school days and plant a few Beans in a box as a practical illustration of the facts stated here.

The first action of the planted Bean is to absorb water to a prodigious amount, and so wake the quiescent life forces which may have been slumbering within it for years. It is a law of animal and vegetable life that all vital processes must be performed in solution. Without water, life is dead or somnolent.

When Nature made the Bean, she left a small opening or window in its skin-wall called the micropyle. Through this opening of the water-swollen seed, now issue two pale sprouts. One is long and pointed; it is the radicle or incipient root. The other is stubbier and is tipped by a cluster of folded, yellow-green leaves; it is the plumule or incipient stem. With unerring exactness, the radicle grows down into the soil and the plumule feels its way up into the air.

By this time, the seed has burst its walls and split into two halves, which indicates that it belongs to the dicotyledonous group of plants. As the seedling continues to grow, these cotyledons begin to shrink and shrivel. The plant is living on their substance until it can begin to make its own. In the case of the Bean, the stem lifts the emaciated cotyledons up into the air, where they act as leaves until the tiny green things at the stem’s tip have expanded into those important organs.

When the first leaves have fully opened and the spent cotyledons have dropped off as mere empty shells, the independent life of the plant may be said to have begun. We are now in a position to examine its methods of living.

Examining the root, we find that by this time it has expanded into many branches. Each tip is a tiny mouth through which the plant drinks the all-important water and mineral salts. Root tips exercise great ingenuity; they feel their way underground, touching here, recoiling there, and searching out the elements necessary to the plant’s economy with wonderful sagacity.

The actual absorption is done by minute filaments or hairs which take in water and its dissolved contents by osmotic action. They secrete a digestive fluid which renders certain minerals soluble, and by a strange intelligence, select the kind and amount of material they take in. In certain groups of plants, notably the Legumes, colonies of Bacteria take the place of root hairs, and by a reciprocal action, provide the plant with the nitrogenous elements which it craves.

The principal food of most vital importance taken in by the roots is nitrogen. Nitrogen is one of the basic elements of protoplasm, the life fluid of the living cell. Where there is life, there is nitrogen. Sulphur, phosphorous, silica, iron and other elements are also needed in small quantities.

The root hairs are constructed so as to allow fluids to pass in but not out. The continual absorption of water results in a mechanical pressure which automatically forces the sap up through the stem to all parts of the plant. The process is aided by the evaporation of water from the leaves, through the partial vacuum created by them at the top of the system. Pushed from below and pulled from above, the sap of a tree, for instance, moves with a propulsive power greater than the blood pressure of the strongest animal.

Above the roots and the stem of the developing plant are the branches. Their function is too well known to need much comment. They raise the leaves up into the air and the light. They act as conduits for ascending and descending sap. They give the plant strength and rigidity. Each main stem is a clever bit of plant engineering, so built as to withstand all kinds of heavy strains and stresses.

The leaves of our seedling are extremely important parts of its anatomy. Pluck them off and it will die in a few hours. They are mouths, stomachs and lungs all in one. Their surfaces are broad and flat, in order that they may catch and devour every particle of carbon dioxide which comes their way. To us, carbon dioxide is a negligible part of the atmosphere, but out of this intangible product of combustion, arising from fires, breathed out by animals and expelled by volcanoes and hot springs, the tallest tree builds its greatest structure. Is it any wonder that it takes so long!

In the inner tissue of each leaf is a substance called chlorophyll. It is the material which gives leaves their green colour. It is one of the most important substances in plantdom. Under the influence of sunlight, this chlorophyll takes the carbon dioxide of the air, and, with water and certain minerals, makes starch, the raw material of plant construction. This process, called photosynthesis, goes on while the sun shines, and stops with the approach of darkness. The necessity of plenty of light cannot be overestimated.

In the manufacture of starch, oxygen occurs as a by-product. As the plant has no use for this element, it is breathed out from the surface of the leaves. From the standpoint of man, this makes plants atmospheric purifiers. At night, when the making of starch is suspended, there is often a superabundance of carbon dioxide within plant structures. It is this gas which is now exhaled, though in very small amounts. Some authorities maintain that the excess of carbon dioxide is contained in water absorbed by the roots. In the daytime this is welcomed as additional starch material, but at night there is no use for it.

Another substance which is always present in excess of plant needs is water. It is essential as a tissue builder and also as a carrier of nourishment. Its continual evaporation from the leaf surfaces furnishes one of the sources of motive power for the circulatory system. The rate of evaporation is controlled by the stomata, little pores or mouths which have contractible lips. In the Lilac there are as many as one hundred and twenty thousand stomata to the square inch. They are nearly always located on the under surface of the leaves.

Certain plants like the Cacti seem to be able to get along without leaves, but thick, fleshy sections of stem perform all their functions. The Fungi and other parasites differ from most plants in that they have no chlorophyll for starch-making but live on the already elaborated tissue of living or dead neighbors.

When our seedling grows old enough, it marries and has a family. Among the higher plants, the sexes are quite distinct. There are such things as male plants and such things as female plants, but more often both sexes occur in the same individual and frequently in the same flowers. The Hop, Nettle, and Date Palm are one-sex plants. Maize has flowers of different sexes on the same stem.

Flowers are the reproductive organs. In the blossom of the Bean, the stamens are the male organs and the pistil is the female organ. The stamens produce dust-like pollen which is conveyed by the wind to the pistil of some other flower. Pollen grains deposited on the stigma of the pistil are held there by a sticky secretion until they can grow a long tube which travels down the style, eventually reaching and fertilizing the tiny ovules or eggs.

The ovules then develop into seeds and the pistil grows into a pod, on both of which the parent plant bends all its energies to give a good start in the world.

The cycle is now complete. We have another Bean and are back to where we started, ready for some other fellow to plant the new Bean and perform the experiment all over again.

This is the story in brief, but there are many other details. The different plants have invented and perfected all kinds of devices to secure the effective propagation of the race. The Hazel and the Grasses hang their stamens out in the wind in order that it may blow their pollen to some other plant, which is waiting with feathered pistil to catch it. Most garden plants depend on the insects to act as pollen carriers and display gorgeous flower-petals and nectar pits with which to attract them. Many plants aim to prevent self-fertilization by having the stamens and the pistil come to maturity at different times.

The plants go to great lengths to secure an advantageous distribution of their offspring. The nature of a plant is to live by growing. When it has reached a prescribed height, it must continue the process by producing new individuals to carry on the cycle. It gives its children a start in the world by providing them with wings, bladders, feathers, spikes, thorns, sticky secretions, submarines, boats, and kites, according to the method of travel they are to use. Sometimes the matured pistil or fruit is dispersed entire. Sometimes it opens and shoots the seeds out. The Violet and Oxalis act like veritable guns, so vigorously do they expel their seeds. There are seed-capsules, like those of the Primrose and Xanthium Spinosum, which open at the top so that only a high and efficient wind can dislodge the seeds.

The problem of food storage is an important one in plantdom. Annuals die when they have flowered and produced seed. Perennials wither but persist for a number of seasons and sometimes many years. Those whose stems or trunks are permanent withdraw their starch and chlorophyll into their cambium layer where it is safe from freezing. Those which die down to the ground each fall store up food material in underground stems and roots in sufficient amount to get a good start the following season. The Potato is an enlargement of the underground stem, but Carrots, Beets, and Turnips are bulbous roots. Hyacinths, Tulips, Daffodils, Snowdrops, Crocuses, and Buttercups all store food material in bulbs. Practically all wild flowers which come up early in the spring, feed upon the nutriment manufactured during the previous season.

Buds represent the foliage of the coming season. Each fall, trees and bushes prepare for next year’s growth by putting forth miniature shoots and leaves folded up in warm brown overcoats. At spring’s urgent call, the buds have merely to cast aside their coverings and step out into the warm sunlight. These buds really make a tree a community of individuals, because each one is capable of reproducing everything that has occurred on the plant up to that point. This is the principle on which grafting is carried on.

The most wonderful thing in all plant structure is the plant cell. There are anywhere from six thousand to twelve thousand of these living units to the square inch. In their restless, moving protoplasm lies the mystery of life--the directing energy which controls the plant’s activities and makes it a conscious, intelligent organism.

IF THIS AGED CEDAR COULD TELL ITS LIFE’S STORY, WE WOULD FIND IT FULL OF ROMANCE AND ADVENTURE

CHAPTER III

Migrations of Plants

“_Race after race of leaves and men
Bloom, wither and are gone;
As winds and water rise and fall
So life and death roll on._”

We are so in the habit of thinking of plants as fixed and static things that it rarely occurs to us that they migrate over the earth’s surface quite as extensively as do men or animals.

While it is probably true that vegetation originated simultaneously at different points on the globe’s surface, not much observation is necessary to indicate that it does not always stay where it is put. Plants are peculiar and native to certain lands in a very definite way, but their love of adventure often carries them to the far corners of the earth. They are the most energetic and effective colonizers in existence. The complete history of plantdom would include the stories of invasions, conquests and revolutions quite as stirring as anything in human annals.

If it is absorbing to follow the racial movements of man, ancient and modern, it is equally fascinating for a lover of plants to investigate their migratory habits. We have exact records of many of their travels and can make interesting conjectures about the rest.

To a layman, the present distribution of plants may seem chaotic. He reads that certain families are natives of Europe and Australia, or North America and Africa and are absent from all intervening countries. The Alpine species Primulas and Saxifrages are common to both the Arctic and the Antarctic. There are fifty-eight European and New Zealand species which are identical. The British Grass Poa Annua is also found in the Andes of Brazil. Through what thousands of years of change and evolution have these things come about! Yet the results are no more complex than was the filling of America with its mixed and conglomerate human population.

In a general way, there is a measure of fixity to plant distribution. Certain plants have elected the tropics as their home; and only under the greatest stress of circumstance can they be induced to go elsewhere.

Tropical heat and moisture make for luxuriance of vegetation. There is a much greater variety there than in the North. Woody Vines climb the tallest trunks, where they intermingle their leaves and blossoms with those of their host. Gorgeous Air Plants beautify and perfume the forest. Stately Palms wave magnificent bouquets of pendulous fronds.

As we travel away from the equator, the vegetation takes on a simpler aspect. There are more annuals and more herbs. The number of Ferns, Grasses, and catkin-bearing Trees, like the Alder and the Birch, increase. The limited growing seasons make for a more restricted accumulation of tissue. Such tropic plants as have braved the rigours of the colder climates have dwindled much in size. The Castor Oil Tree becomes a humble annual (Ricinus Communis) only three to eight feet in height. Other tropical trees become so small that temperate zone folk tread them under foot.

When we get into the polar regions, all the plants take on a stunted and dwarfed appearance and, in some cases, retire almost entirely under ground. The number of genera and species is much reduced. The Oak, Walnut, Chestnut and Elm are replaced by the hardy conifers. At the point where vegetation becomes almost extinct are dwarf Birches, Willows and polar Blackberries (Rubus Arcticus). The simple Mosses and Lichens mark the last lingering evidences of life.

A curious feature of plant life in the polar regions is the rapid growth which it often exhibits. The summer of the Far North is short but it is one day of intense and blinding light. The sun shines continually throughout each twenty-four hours. By virtue of its stimulating power, plants are able to perform in a few weeks processes of development which take months under ordinary conditions.

It is illuminating to take a single country in a more favoured climate and, as far as possible, trace its plant history. The British Isles, because of their limited area, are a convenient field of study. An investigation of their settlement by plants gives us many hints about prehistoric climatic and geographical changes.

Geologists generally believe that the British Isles were once joined to the mainland of Europe. It was at this time that they were settled by vegetation. Some of this plant life came from Spain and some from southwest France; there was also a Germanic group. The floating ice of the glacial period brought over hardy visitors from the Scandinavian peninsula. A few plant immigrants arrived from North America and landed on the west coast of Ireland.

St. Helena is an isolated volcanic mass built up seventeen thousand feet from the bed of the ocean. It therefore has its own peculiar vegetation, a portion of which is believed to have been evolved on the spot from the one-celled state. According to Sir Joseph Hooker, forty out of fifty flowering plants and ten out of twenty-six Ferns “with scarcely an exception cannot be regarded as very close specific allies of any other plants at all.” Sixteen of the Ferns are common to Africa, India or America and were probably carried there by the wind. Ocean currents also brought other species from Africa.

In 1883, a most interesting thing occurred on the Asiatic island of Krakatoa. A violent volcanic eruption wiped every vestige of life off its surface. When the flow of lava ceased and the earth cooled once more, Krakatoa was to all intents and purposes a volcanic island newly risen from the sea. It presented the exact analogy of a recently created bit of land waiting to be settled by the plants. In 1883, it was as barren as the face of the moon. In 1888, a Mr. Hemsley described its appearance as follows:--

“The first phase of the new vegetation, was a thin film of microscopic fresh-water Algae, forming a green, slimy coating, such as may often be seen on damp rocks, and furnishing a hygroscopic condition, in the absence of which it is doubtful whether the Ferns by which they were followed could have established themselves. Both Algae and Ferns are reproduced from microscopic spores, which are readily conveyed long distances by winds. Eleven species of Ferns were found, all of very wide distribution, and some of them had already become common the fourth year after the eruption. Scattered here and there among the Ferns were isolated individuals of flowering plants, belonging to such kinds as have succulent seed-vessels eaten by birds, or such as have a light, feathery seed-vessel like the Dandelion and a host of others, and are wafted from place to place by the winds.

“On the seashore there were young plants and seeds (or seed-vessels containing seeds) of upwards of a dozen other herbs, shrubs and trees, all of them common on coral islands, and all known to have seeds capable of bearing long immersion in sea water without injury. Among the established seedlings were those of several large trees, and a Convolvulus that grows on almost all tropical coasts, often forming runners one hundred yards in length. There were Cocoanuts also, though none had germinated.”

The farther such an island is from the land, the longer will vegetation take to get established. Darwin found that the isolated islands of Keeling, after thousands of years of existence, contained only twenty kinds of flowering plants.

Although plants have no legs they are not devoid of mobility. When man uses the propulsive power of steam to travel by, he shows no greater ingenuity than do plants in their use of special devices of locomotion.

Species like the Tumble Weed (Amarantus Albus) pull up stakes, and, consigning themselves to the swift autumn winds, race across country at great speed, scattering seeds as they go. The Utriculariae or Bladderworts are true sailors and float about on inland streams like little ships. The Duckweeds and Wolffias also have aquatic habits.

However, most plants prefer to travel in embryo. In the form of small and microscopic seeds the force of gravity has little influence on them, and they can journey for long and incredible distances.

To this end practically every seed in existence is provided with some apparatus or appendage designed to help it make its way in the world. The Elm, the Linden, and the Ash bear winged seeds, which are so efficient in riding the breeze that they are really miniature aeroplanes. The double wings of the Maple are very much like those of an insect. The seeds are released from their container in such manner as to acquire a whirling motion as they fall.

The progeny of the Willow is provided with long projecting hairs which curl together to form a tiny balloon. Feathery attachments called pappus enable the children of the Dandelion, the Thistle and the Fire Weed to go on long jaunts of exploration.

The seed-pods of the Sycamore are great rollers. Even ordinary nuts and fruits may be blown to considerable distances by the strong winds of autumn. The many edible seeds and fruits are carried gratis by birds and animals. The Mistletoe, for instance, is distributed entirely by them.

Walnuts, Butternuts, and Acorns bear water travel well, as do certain of the hard seeds. The Arrowhead (Sagittaria) has a self-made water-wing on which its offspring float.

Plant seeds, which like to travel on animals, all provide themselves with grappling irons in the shape of sharp hooks, spurs and spines with which they cling to their carriers. Everybody in the northern United States knows of the avidity with which the Cockle-bur clings to any passing object. The Touch-me-not (Impatiens), the Wistaria, and a host of others, actually shoot their seeds from their pods as from a gun.

Every vagrant breeze, every purling brook, every deep river, every ocean current, is a highway of travel in plantdom. The birds, the beasts, the insects, and not least, man himself, are involuntary vehicles on which our vegetable friends tour the world. The spores of Mosses, Lichens, Fungi and other cryptogams are so light that they find no difficulty in mounting into the air and traveling across the Atlantic or Pacific Oceans at will.

The complete record of plant conquests would fill many volumes. Their operations have extended into every land and have had influence on the world’s history. It very often happens that plant invaders become so quickly and thoroughly naturalized in a strange country that they go a long way toward supplanting the original inhabitants in a very short time.

It was Darwin who first noticed the extensive conquests of the Cardoon Artichoke (Cynara Cardunculus) in South America. In one section, these prickly plants covered an area of several hundred square miles, having entirely superceded the aborigines.

It is well known that the most troublesome of the American weeds are of British origin. On the other hand, the American water weed Anacharis blocks up small English streams. The grass called Stipa Tortilis has captured the steppes of southern Russia. The love of change seems to be an inherent tendency in plantdom. The Pigweed and the Morning Glory have come north from the tropics. The Canada Thistle, originally a foreigner in North America, has spread all over Canada and New England. The American Erigeron Canadense has emigrated to all parts of the world. The flora of Scandinavia, like its people, are aggressive colonizers. More than one hundred and fifty species have reached New Zealand alone and nearly as many have established themselves in the eastern United States.

Some plants seem to be able to adapt themselves to any climate and therefore are born explorers, but the greater number are too fastidious regarding conditions of soil, heat, light and moisture to thrive well everywhere. It is a noticeable fact that the most successful plant invaders usually come in the wake of human colonizers and stick to the sphere of man’s influence. For example, the Butter-and-Eggs (Linaria Linaria) has followed the railroad tracks almost entirely over the tropical and semi-tropical world. Sometimes, however, hardy plants advance into the primeval jungle, there to give battle to its lusty inhabitants.

On the whole, annuals have a better chance than perennials to gain a foothold in a new country. Every spring the weeds, grasses, and common flowering plants have to start all over again from a seed beginning. The spores of newcomers, therefore, have almost an equal chance with the established inhabitants. On the other hand, the bodies of perennials occupy the land in close-packed ranks all the year, ready to dispute every inch of ground with an aggressor. It is very hard for new plants to gain entrance into a well-grown forest.

Man has been of tremendous aid in the distribution of plants over the earth’s surface. Either consciously or unconsciously he takes his plants with him wherever he goes.

It was the Emperor Chang-Chien who carried the Bean, Cucumber, Lucerne, Saffron, Walnut, Pea, Spinach and Watermelon from Asia to China about 200 B. C. The period of Roman conquest was a great epoch in the history of plant migrations. The Peach and the Apricot first became prominent as fruits at that time. Roman generals introduced the Pear, Peach, Cherry, Mulberry, Walnut and many ornamental shrubs into England.

From an obscure native of Bengal, the Sugar Cane has become an important plant of wide distribution. Coffee, a wild berry of Arabia, is now the chief crop of whole countries in the West Indies and South America. The yellow Maize of America has become a citizen of the world. The weak and humble Wheat is the sole possessor of thousands of square miles of land in America, Russia and elsewhere.

All this has been wrought by man’s efforts. When it is to his interest, he fights the battles of plantdom, and because of his superior knowledge and equipment is of tremendous service. Sometimes, however, he gives aid to his plant friends through motives that are quite unselfish. A romantic story is related of a French naval officer named Declieux who once elected to carry a Coffee Plant to the Colony of Martinique. The supply of water ran low during the voyage, and, rather than see the plant die, the man shared his daily glass with it, at considerate discomfort to himself.

Until man becomes all-wise, he will continue to make mistakes; and not least of these will be in connection with his investigations into the mysteries of Nature. It has happened more than once that he has introduced some new plant into an old land, or vice versa, and lived to thoroughly regret his action.

Sometime in 1890, a generously inclined individual threw a Water Hyacinth into the St. Johns River in Florida. In the space of a few short years, that single plant had multiplied so prodigiously as to seriously impede navigation, lumbering and fishing.

Jack London tells of a similiar thing that happened in Hawaii: “In the United States, in greenhouses and old-fashioned gardens, grows a potted flowering shrub called Lantana; in India dwells a very noisy and quarrelsome bird known as the Myna. Both were introduced into Hawaii--the bird to feed upon the cut-worm of a certain moth; the flower to gladden with old associations the heart of a flower-loving missionary. But the land loved the Lantana. From a small flower that grew in a pot, the Lantana took to itself feet and walked out of the pot into the missionary’s garden. Here it flourished and increased mightily in size and constitution. From over the garden wall came the love call of all Hawaii, and the Lantana responded to the call, climbed over the wall, and went a-roving and a-loving in the wild woods.

“And just as the Lantana had taken to itself feet, by the seduction of its seed it added to itself the wings of the Myna, which distributed its seed over every island in the group. From a delicate, hand-manicured, potted plant of the greenhouse, it shot up into a tough, and belligerent swashbuckler a fathom tall, that marched in serried ranks over the landscape, crushing beneath it and choking to death all the sweet native grasses, shrubs and flowers. In the lower forests, it became jungle, in the open, it became jungle only more so. It was practically impenetrable to man. The cattlemen wailed and vainly fought with it. It grew faster and spread faster than they could grub it out.”

Then ensued a battle royal between man and plant. The man called to his aid hosts of insect mercenaries. “Some of these predacious enemies of the Lantana ate and sucked and sapped. Others made incubators out of the stems, tunnelled and undermined the flower-clusters, hatched maggots in the hearts of the seeds, or covered the leaves with suffocating fungoid growths. Thus simultaneously attacked in front and rear and flank, above and below, inside and out, the all-conquering swashbuckler recoiled. Today, the battle is almost over, and what remains of the Lantana is putting up a sickly and losing fight. Unfortunately, one of the mercenaries has mutinied. This is the accidently introduced Mani Blight, which is now waging unholy war upon garden flowers and ornamental plants, and against which some other army of mercenaries must be turned.”

Such unfortunate occurrences are sure to become more and more infrequent as plant emigration and immigration finds itself under increasingly drastic governmental regulation.

The Foreign Seed and Plant Introduction Service of the United States Department of Agriculture makes a scientific examination of all plants brought into the United States for propagation purposes. It rids them of objectionable Bacteria and insect pests and refuses them admittance entirely if its experts decide that the newcomers will be harmful or injurious in any way.

The agents of the Service are constantly scouring the far corners of the earth for new and rare plants. In the twenty-four years of its existence it has introduced from abroad some fifty thousand specimens of seeds and plant cuttings. Some of the successful immigrants have been Feterita (from Egypt), Sudan Grass, Bamboo and Alfalfa. New Zealand has yielded new types of Potatoes. Dwarf Almonds and strange Cherries and Apricots have come from Turkestan. All these have proven of commercial importance, as has Durum Russian Wheat, credited with opening up new areas in the Northwest, and the Navel Orange from Brazil which has created for itself a California industry covering thirty thousand acres and valued at fifteen million dollars per annum.

Painstaking and scientific methods are best when man attempts to aid Nature in her evolutionary processes, especially when they are in connection with the migration and distribution of plants.

CHAPTER IV

COMRADES OF THE PLANT WORLD

“... which links by a fraternal tie The meanest of His creatures with the high.”

--Lamartine

The first and greatest problem for every terrestrial creature is to live. The chief means of doing so is to eat. Therefore, the relation of being to being and species to species is dominated by the necessity for food. Among man this fact is somewhat masked and obscured, but in the rest of the world it is entirely plain and obvious. Again and again on every hand, we see that plant, animal, and man all maintain their life impulses by consuming the tissue of their fellows.

In view of this fundamental fact, we can afford to look with some degree of charity upon that class of plants which are termed parasites. These interesting creatures are merely carrying out in a very direct and apparent way a principle which permeates all domains of life. A Tiger kills its prey; an Ox devours unoffending Grass; the parasitic Dodder robs some healthy neighbour of part of its juices.

The word “parasite” originally referred to a member of a college of priests who had their meals in common. Later, it came to mean living at another’s expense, as large numbers of people did in classical times. When one realizes that there are twenty-five hundred species of parasitical seed plants, he hesitates to brand them all as thieves and degenerates. Taking into consideration plants which depend upon the soil fungi for part of their sustenance, we should have to call half the seed plants in the world “parasites.” On a basis of strict accountability, it would also be necessary to classify all fruits as “parasites” as they draw nourishment from the parent boughs and give no return.

The fact is there are very few plants which are not more or less dependent upon some living fellow creature for their food supply. Sometimes the relation is strictly reciprocal; sometimes the advantage appears to greatly favour one or the other of the participants. In other cases the occurrence arises accidently through chance proximity, without a conscious pact or deliberate contract.

Edward Step in his illuminating book Messmates sums up the matter admirably: “Two friends in good health, each able to earn his own living, agree for the sake of companionship to live together, but each defraying the cost of his own necessities and luxuries. This is a case of mutualism. Two other friends also agree to share quarters and have a common table; but one may be infirm and wealthy whilst the other is strong and comparatively poor. The infirm one offers to pay two-thirds of their common expenses if the other will contribute one third, plus his protection, cheerful companionship or other valuable help. This is a commensalism. The pair are messmates, each contributing to hotch-potch according to his ability or endowment, each affording what the other lacks, and both, therefore, benefitting from the partnership.”

It must be admitted that there are cases of plant companionship in which, to all human perception, the material benefits seem directly one-sided, but who can conclusively deny that the nourishment-giving partner may not receive some psychic or spiritual benefit from the union? The Orchids and many other tree-parasites bear flowers of exquisite beauty. Can we be quite sure that the trees do not like to adorn themselves with gorgeous ornaments of this kind? Such a desire would be quite natural.

Plants which are low and weak in the scale of evolution are very prone to enter into symbiotic relations. The Lichens are compound organisms in which green Algal cells live between fungous threads. The Fungus sucks up the water and mineral salts from the soil and the Alga combines them with carbon dioxide from the air to form palatable food for both. Such plant-partners have been observed to live together amiably for twenty-five years or more.

The Fungi and all plants which are “pale, fleshy, as if the decaying dead with a spirit of life had been animated” have no chlorophyll, the mysterious green substance which is necessary for the production of starch. They must either make alliances with plants which possess this vital elixir or live on decaying matter which contains elaborated food material. Many choose the latter course, but a goodly number, especially those of primitive structure, have entered into profitable partnerships.

The minute one-celled plants called Zoochlorella or Zooxanthella have chosen the fresh water sponge Ephydatia Fluviatilis for their messmates. Sometimes they live with the Hydra called Viridis and impart to it a bright green colour.

There are whole regiments of microscopic parasites which thrive on living plant tissue and cause spots and rust to appear on Apples, Peaches, Pears and other fruits and number among their cohorts Rose-blight, Wheat-rust, and various Mildews. The larger messmate does not receive very much benefit from the relation, in this instance, except when the minute guests serve to cover a cut or an abrasion with a protective mantle, just as Mildew shields cheese or jelly from decay.

Cases where Fungi render very valuable services to larger plants are exemplified by the Monotropa or Indian Pipe. This pallid scavenger grows on the decaying vegetable matter of the woods. It toils not, neither does it make plant starch, but it is able to produce pretty, ghostly flowers and white scale-like leaves. On its roots thrive species of Fungi which perform the part of root hairs and in return receive nourishment from their host. Certain authorities claim that the Fungi get the better of the bargain, as the Monotropa has been known to maintain its health without them in laboratories. But the fact is the relation does exist with undisputed benefit to both parties.

Beech Drops germinate in contact with roots of the Beech tree, attach themselves there and raise yellow, seared stems covered with scales instead of leaves but bearing perfect flowers. The Broom-Rapes get their nourishment from the roots of Tobacco and Hemp in the same way.

Prominent among the larger parasitic plants is the Dodder or Devil’s Thread. This vine derives all its sustenance from other plants and, as far as can be determined, gives no material return. From this standpoint, the Dodder is a robber pure and simple, a degenerate outcast from the community of decent plants. From the viewpoint of this chapter, it is possible to believe that the host of the Dodder derives some spiritual or hidden material benefit from the union which makes it distinctly worth while. If such were not the case, it would seem that, through ages of evolutionary development, such plants as Flax would have devised means to escape the Dodder’s clutches.

The Dodder inhabits low ground and pokes an inquiring head above the surface each spring much like any self-sustaining plant. However, it is not long before it attaches itself to some lusty neighbour by root-like suckers, which pierce the stem and extract the nourishing juices. If the supply seems adequate, the Dodder winds its yellow, yarn-like tendrils about the host and allows the roots which connect it to the earth to wither. Its absorbing tubercles look like caterpillar feet; their cells form a perfect graft with the host and gradually disperse through its body. If other plants are near enough, the Devil’s Thread will reach out and tap their food supplies also. A single Dodder has been known to draw nourishment from five or six other plants of different families at the same time, thus indicating that it must have digestive machinery enough to appropriate these varying saps to its own uses. The Dodder has no chlorophyll and therefore no leaves but bears pretty little bell-like flowers which later produce seed.

In the tropical jungles are many parasites of brilliant aspect, which, having no leaves or root hairs, germinate directly on supporting plants and apply suckers to the tissues of their hosts. When seen from the ground, their short stems make them seem all flower, and often very handsome ones. The Rafflesia Arnoldi of Sumatra is a notable example.

Man cannot help condemning such plant practices. Yet all Nature is a struggle for existence. Does it not require some courage and hardihood to come out and do in a bold and open way what the rest of the universe is doing by indirect or underhand methods?

The beautiful Orchids belong to a botanic group of Epiphytes which may be classified as guests or lodgers. Being green, they are able to gather their own living from dust, rain and carbon dioxide in the air. All they ask from their tree-hosts is a branch on which to perch. There are probably few trees which are not delighted to have such delicate, fairy-like creatures add to their own beauty and charm. They wear them much as a woman wears a rose in her hair.

In America there are well-mannered parasites such as the decorative Spanish Moss so common throughout the South. This plant is normal in all respects; except that, perched on a kindly tree, it draws all its nourishment from the air instead of through soil-piercing roots.

The Mistletoe is a perfect example of a mutualist. Early in its aerial life, it sends a root through the bark of its tree companion and during the spring and summer, absorbs much food. When winter days come, and the tree has lost its leaves, the grateful messmate reverses the process and sends into the heart of its friend the larger part of the nourishment which it has been able to store up during the prosperous weeks of summer. The seeds of the Mistletoe are interesting because they are covered with a sticky fluid which enables them to travel from tree to tree on the feet of birds.

That some plants are parasites from necessity or laziness rather than choice is indicated by a Brazilian variety of the Cuckoo-Pint which sits far up on some tree branch and, like an immense spider, sends down to the earth long delicate tubes through which it sometimes sucks food and water.

One of the most interesting facts in plantdom is the alliance maintained by Clovers, Beans, Vetches and other leguminous plants, with Bacteria belonging to the class Pseudomonas. No soil can be fertile unless it contains organic compounds of nitrogen. The earth Bacteria have discovered methods of producing these important substances, possibly extracting nitrogen distributed through the ground. These minute parasites attach themselves to the roots of the larger plants, which promptly enclose them in cysts or nodules where they can lead a sheltered life and manufacture assimilable food compounds for their hosts. When they die, the owners of the roots feed upon their bodies.

What is the art of grafting but a form of artificial parasitism? Very often a branch or cutting is made to form a bodily union with some plant of an entirely dissimilar species. In some cases, the intruder sends roots into the tissue of its host like a true dependent. Grafts of Prickly Pears, Mexican Grapevines and Agaves put forth food-suckers in the soft flesh of the Giant Cactus or the Barrel Cactus much as they would do if planted in the earth. There is here no true diffusive union of partners but mere absorption on the part of the invader.

Even grafting of allied species of Grapes sometimes results in the young plants sending roots through the tissues of the scion, eventually reaching the earth by way of the body of the host. In such cases, the parasite also draws nutriment from its messmate by means of a superior osmotic pressure.