FIG. 102.—BRAZILIAN OR PARA RUBBER (Hevea brasiliensis) Native in the Amazon region, but now much grown in the East Indies.FIG. 102.—BRAZILIAN OR PARA RUBBER(Hevea brasiliensis)Native in the Amazon region, but now much grown in the East Indies.
This Brazilian tree, a native of the rich rain forests of the Amazon, isHevea brasiliensis, and a relative of our common spurges of the roadsides and of the beautiful crotons of the florist, all belonging to the familyEuphorbiaceæ. The first important notice of this rubber appears to be by the astronomer C. M. de la Condamine, who was on an astronomical trip to the Amazon in 1735. He describedPararubber, as it has since been called, and by 1827 the export of this gum had grown to 31 tons a year. In 1910 Brazil exported over 38,000 tons, nearly all of which was collected from wild trees. After the discovery of vulcanization the demand for all kinds of rubber increased by leaps and bounds and it became obvious that the wild trees,although tapped regularly, would not supply all of the necessary amount. For years the Brazilian Government protested the export of seeds or other means of growing the plant out of the Amazon, but in 1876 H. A. Wickam chartered a steamer and loaded her with 70,000 seeds of para rubber trees and some crude rubber, and had the ship passed by the Brazilian port authorities as loaded with “botanical specimens.” He safely transported the cargo to the Kew Gardens, London, where only about 4 per cent of the seeds ever germinated. From there the young plants were sent to India, where now, and in the Straits Settlements and the adjacent islands, there are huge plantations of para rubber. From the wildest speculation in rubber shares on the London Stock Exchange, which followed the successful introduction of the plant into British possessions, the industry has now settled down to be one of the most profitable in plant products of the East.
The rubber of bothHeveaandCastillais produced from the milky juice or sap of the trees and is actually a wound response. As the trees are tapped thelatex, as the milky juice is called, runs out of the wound and upon reaching the air coagulates. This material is removed and a new wound made, a process which is repeated for several years. There is still work to be done upon the problem of how often plantation trees should be tapped to get the greatest flow of latex without injuring the tree, but in many plantations it is done every day or every other day in the season, some rubber planters allowing a resting period during leaf fall, others again tapping almost continually. The actual wound is made by removing just enough bark to induce a flow of latex, but not until the wound is completelyhealed, a process taking from four to six years, can that particular part of the bark be cut again. With almost daily tappings the problem of finding fresh pieces of bark into which the cut may safely be made has been developed into a fine science. In the wild trees of Brazil it is still done by natives, probably rather wastefully. Rubber plantations in the tropical regions of Asia now total over a million acres, as compared to only slightly over 200,000 acres in the American tropics and from all other non-Asiatic sources. Of this probably 100,000 acres are in Africa. At the present time nearly half the world’s supply of rubber comes from these plantations, the balance still coming from Brazil.
There are two other rubber-producing plants, neither of which are as important asHeveaandCastilla. One is the common rubber plant so much grown as a house plant and said to be much cherished for that purpose in Brooklyn. It is a kind of fig tree, known asFicus elastica, a native of India and the source of India rubber. It was used for years, before the days of vulcanization, mostly for lead-pencil erasers. Thousands of acres of it in India were recently destroyed to make room forHevea, although it still produces a respectable amount of rubber, inferior, however, toHeveaandCastilla. In Mexico a new source of rubber is the guayule rubber plant, a small shrub native of the drier parts of the Mexican uplands. It does not produce latex, as practically all other rubber plants do, but particles of rubber are found directly in its tissues, mostly in the bark. While of some importance, this shrub, known asParthenium argentatum, a member of theCompositæor daisy family, is notlikely to become a dangerous rival of either Para orCastillarubber. Wild sources of guayule rubber are already reported as diminishing rapidly, so that its permanent success will depend upon cultivation. At least a score of other plants are known to produce rubber of a kind, but none of them have yet been much developed. From most plants with a milky juice, such as dogbane or spurge, rubber of some sort can usually be recovered. The production of this substance is directly due to a response of the plant to wounds, and there are still great fields of research necessary on this phase of plant activity, upon which a great industry has already been built.
Nearly all the drugs and medicines of importance are of vegetable origin, and from the days of Theophrastus the study of plants as possible medicines has been one of the chief phases of botanical research. In the early days all that was known about plants was learned by men interested in medicine, and some of their quaint old books are interesting relics of a bygone day. At present, pharmacognosy, or the science of medicinal plant products, is a highly developed specialty taught in medical and pharmacy schools. And yet the greatest medical college in this country has recently issued instructions to its staff of doctors and nurses to pay particular attention to “old wives’ remedies,” most of which consist of decoctions of leaves and other parts of plants. They have done this because all the knowledge of the scientists regarding medicinal plants has its origin in the habit of simple people turning to their local plants for a cure. The accumulation of the ages, aided and guided by the scientist,has resulted in the wonderful things that can now be done to the human body through the different drugs, nine-tenths of which are of plant origin.
There is almost no part of a plant that, in some species at least, has not been found to contain the various acids, alkaloids, oils, essences, and so forth, which make up the chief medicinal or, as the pharmacists call it, the active principle of plants. In certain of them the most violent poisons are produced, such as the poison hemlock which killed Socrates, and the deadly nightshade. And again the unripe pod of one plant produces a milky juice so dangerous that traffic in it is forbidden in all civilized countries, and yet later the seeds from that matured pod are sold by the thousands of pounds to be harmlessly sprinkled on cakes and buns by the confectioners. Earlier in this book it was said that plants are chemical laboratories, and nowhere has this alchemy been carried to such a pitch of perfection as in the hundreds of drugs produced by different plants. Reference to special books on that subject should be made by those interested, as only a few of our most important drug plants can be mentioned here.
The Spanish viceroy of Peru, whose wife, the Countess del Chinchón, was dangerously ill of a fever in that country about 1638, succeeded through the aid of some Jesuit priests in curing the malady, with a medicine which these priests had gotten from the natives. It was a decoction from the bark of a tree, and its fame soon spread throughout the world as Peruvian bark. Even in those days malaria was the curse of the white man in tropical regions, and sincethen it is hardly too much to say that the discovery of this drug has made possible for white colonists the retention of thousands of square miles of tropical country that without it would in all probability be unfit for occupancy. To the natives, too, quinine has been one of the greatest blessings, and in some of the remote regions of the tropics the writer has found quinine more useful than dollars in getting help from fever-ridden natives, too poor and too remote from civilization to get the drug.
For more than a hundred and fifty years after the discovery of Peruvian bark it was always taken as a liquid, usually mixed with port, and an extremely noxious and bitter drink it made. The fine white powder which we now use in tasteless pellets or pills has made the drug even more useful than before.
The trees from which the bark is used all belong to the genusCinchona, named for the first distinguished patient to benefit by it, and belong to theRubiaceæor madder family. There are at least four or five different species. For many years Peru and near-by states were the only source of the bark, and the English became convinced that the great trade in the drug would exterminate the tree, so in 1880 they introduced the plant into India. These cinchona plantations now provide most of the world’s demand, and some idea of what that means may be gleaned from the fact that in Ceylon alone over fifteen million pounds of the drug are produced annually. In India itself the plantations are largely government owned and quinine is sold in the post offices at a very low rate. In cinchona plantations strips of the bark are removed, and after a proper periodof healing, the process is repeated. It takes about eight years before it is safe to begin cutting the bark.
Most doctors use aconite for various purposes and it is mentioned here chiefly as illustrating a common characteristic of many medicinal plants. The whole plant is deadly poisonous, and in the root there appears to be a concentration of this poisonous substance, which makes the plant one of the most dangerous known. All of the drug aconite is derived fromAconitum Napellus, a monkshood, belonging to the buttercup family. It is a perennial herb with beautiful spikes of purple-blue flowers, not unlike a larkspur, and is a native of temperate regions of the Old World. A related Indian species has been used for probably thousands of years by the natives. They poison their arrows with it and so deadly is the drug that a tiger pricked by such an arrow will die within a few minutes. It is conceded to be the most powerful poison in India. Numerous accidents have resulted in Europe from careless collectors of the roots of horseradish, who sometimes get aconite roots mixed with that condiment, usually with fatal results.
So many other plants are violently poisonous, and yet yield the most valuable drugs, that the greatest care has to be used in their collection and preparation. The habit of many children of eating wayside berries should be discouraged, as some of our most innocent-looking roadside plants are actually deadly if their fruits or foliage are eaten. Fortunately only a very few plants are poisonous to the touch, notably poison ivy and poison sumac, and some of their relatives.
Almost no plant product has caused more misery and relieved more pain than the juice of the unripe pod of the common garden poppy,Papaver somniferum. From it opium is extracted, the chief constituent of which is morphine. If tea can be said to have precipitated our war of independence, opium was indirectly the cause of the opening of China to the western world. The degrading effects of opium had become so notorious that the Chinese in 1839 destroyed large stocks of it, mostly the property of British merchants, and prohibited further importations. In the subsequent negotiations which ended in war, China was opened up to trade. No civilized country now openly permits the sale of opium, although there is still a good deal of it used in practically all parts of the world. The effects of lassitude, subsequent ecstasy, and stupefaction are due to an alkaloid, the continued use of which forms a drug habit of serious consequences. Parts of China, Turkey, Persia, and Siam are said to be still large users of opium which is chewed, or more often smoked. Until comparatively recently fifteen out of every twenty men in some of these countries were regular users of the drug. The legitimate use of morphine by physicians has done more than almost anything else, with the possible exception of cocaine, to relieve suffering, and there is consequently a considerable trade in the drug.
The home of this poppy is unknown, as it has been cultivated from the earliest days. The ancient Greeks and Romans knew it and the Egyptians grew it for opium. It is still grown in India and China, where, notwithstanding vigorous governmentalmeasures, there is a large opium consumption. After maturity the pods of the poppy, from whose milky juice in its earlier stages the drug is obtained, produce many seeds. From these an oil is pressed which is widely used as a cooking oil in the East, and is perfectly harmless. The seeds are also used as bird seed and by confectioners.
FIG. 103.—COCAINE PLANT (Erythroxylon Coca) Native in northern South America. The fresh leaves of this are used as a valuable but harmless stimulant by the natives.FIG. 103.—COCAINE PLANT(Erythroxylon Coca)Native in northern South America. The fresh leaves of this are used as a valuable but harmless stimulant by the natives.
In the northern part of South America the Peruvians and some of their neighbors were discovered by early explorers to be chewing the leaves of a native shrub, apparently with much profit and no evil after effects. It served them much as the betel nut does to the natives of India and other regions of the tropical East. With scanty or no food this apparently harmless intoxicant will carry both men and women over periods of severe fatigue. Theshrub bearing these leaves is not over four or five feet tall and has bright green foliage and small white flowers.
Quite different in its effects has been the drug which has been extracted from this plant, known asErythroxylon Coca. Far from being a beneficial and harmless stimulant, cocaine is now one of the drug evils of our time. Its use, outside that prescribed by physicians, is forbidden practically everywhere, but its consumption in this country, aside from its great and legitimate use as a relief from pain, is still very large.
The number of drug plants is legion, so large in fact, that volumes have been filled with descriptions and notes about them. A few of the most important, omitting those already mentioned, are listed below:
Not until 1492 was the use of tobacco known to the Europeans, when Columbus found the natives of Cuba and Santo Domingo both chewing and smoking it. Subsequent Spanish explorers of the mainland found its use almost universal both in North and South America. It had apparently been used there for countless ages, as smoking it formed part of the most solemn ceremonial rites both of the natives’ religion and their political gatherings. Brought to England in 1586 by Ralph Lane and Sir Francis Drake, the smoking of tobacco spread with the great speed that such a comfortable habit might be expected to exhibit. Notwithstanding violent opposition by certain priests and physicians and other more intolerant opponents of the weed, its use increased throughout the world. To-day, in spite of our modern anti-tobacco fanatics, over two billion pounds are produced annually, and in the United States there is a per capita consumption of over five pounds per year, greater than any country in the world, save Belgium.
All of the many different forms in which tobacco is used are derived from the leaves ofNicotiana tabacum, or perhaps one or two other species of the genusNicotiana, which belongs to theSolanaceæor potato family. There are many other species, all natives of the New World, but the actual home of the tobacco plant is in some doubt. As in so many cultivated plants, which have been grown for countless ages, wild specimens are practically unknown. The plant seeds freely and consequently frequently escapes from cultivation, so that in many parts of America apparently wild plants are to be found that
Temperate Forest on Gardiner’s Island, Long Island, N. Y. Note the open vista through the trees, and lack of undergrowth, due to the forest canopy, and contrast with the profusion of the under vegetation in the rain forest (Courtesy of Brooklyn Botanic Garden.)Temperate Forest on Gardiner’s Island, Long Island, N. Y.Note the open vista through the trees, and lack of undergrowth, due to the forest canopy, and contrast with the profusion of the under vegetation in the rain forest (Courtesy of Brooklyn Botanic Garden.)
Temperate Forest on Gardiner’s Island, Long Island, N. Y.Note the open vista through the trees, and lack of undergrowth, due to the forest canopy, and contrast with the profusion of the under vegetation in the rain forest (Courtesy of Brooklyn Botanic Garden.)
Rain Forest. Root-climbing lianas on a tree stem in the south Mexican rain forest (State of Chiapas). Below: Sarcinanthus utilis, with bipartite leaves. Farther up: Araceæ. Highest of all: epiphytic shrubs are visible near leaves of Araceæ. Around the stem, the cord-like aerial roots of Araceæ on the branches of the tree. (A photograph by G. Karsten.) (After Schimper. Courtesy of Brooklyn Botanic Garden.)Rain Forest.Root-climbing lianas on a tree stem in the south Mexican rain forest (State of Chiapas). Below: Sarcinanthus utilis, with bipartite leaves. Farther up: Araceæ. Highest of all: epiphytic shrubs are visible near leaves of Araceæ. Around the stem, the cord-like aerial roots of Araceæ on the branches of the tree. (A photograph by G. Karsten.) (After Schimper. Courtesy of Brooklyn Botanic Garden.)
Rain Forest.Root-climbing lianas on a tree stem in the south Mexican rain forest (State of Chiapas). Below: Sarcinanthus utilis, with bipartite leaves. Farther up: Araceæ. Highest of all: epiphytic shrubs are visible near leaves of Araceæ. Around the stem, the cord-like aerial roots of Araceæ on the branches of the tree. (A photograph by G. Karsten.) (After Schimper. Courtesy of Brooklyn Botanic Garden.)
trace their origin to cultivated plants. The antiquity of its culture may be gauged by the fact that in the most ancient Aztec tombs elaborately carved tobacco pipes have been found.
The plant is grown as a field crop in rows from one and one-half to three feet apart and set about fifteen inches apart in the row. From the time the seed is sown until the harvesting of the leaves is usually three or four months, during which the plants demand the best of culture. In the United States thousands of acres of tobacco are now grown under cheesecloth shades, an expensive process which is more than compensated for by the improved flavor.
Once the tobacco is cut there begin chemical changes in the leaves that are of great importance to its subsequent flavor and use. These are aided or induced first by a process of curing, which is accomplished by suspending the wilted leaves in the sun, a process that has been practically abandoned for curing by artificial heat. The leaves are hung in a building where slow fires bring the temperature up to 150 degrees F., which is maintained for a few days. The cured tobacco is then gathered into small bundles which are stacked or packed so closely that fermentation begins, often generating a temperature of 150 degrees F. The bundles are then reshifted and the process allowed to start again, which may be done several times, depending upon the quality of the leaf, flavor desired, and commercial requirements. Enzymes and bacteria play a large part in the fermentation process and inoculation of poor grades of tobacco with the organisms of finer grades has been tried. After fermentation has been stopped practically all tobaccosare aged for at least two years, some for longer periods.
In Cuba, where its use was first noticed, the finest tobacco in the world is still produced, notably in the province of Pinar del Rio. It is still something of a mystery as to what peculiar combination of soil, climate, or handling the unquestionable superiority of the Cuban leaf is due. For one thing it is grown in the open, without shade, and is never cured by artificial heat. Nor is the very excellent cigarette tobacco of Turkey ever artificially cured. But attempts to imitate the conditions under which these finest grades of tobacco are produced outside Cuba and Turkey have never been really successful, so that those countries have practical monopolies on the production of the finest cigars and cigarettes. The weed is cultivated nearly throughout the world, even Canada producing considerable quantities, but the best kinds and greatest production is in warmer regions. It is second only to the sugar crop in Cuba, and the United States produces over one-third the world’s total supply. Immense quantities are grown, however, in India and Sumatra, and in the Philippines.
Perhaps the most unusual and localized conditions of climate and subsequent handling are found in the production of perique tobacco. All the world’s supply is grown on a ridge at Grand Point, in the parish of St. James, Louisiana. The leaves are subjected to great pressure and the expressed juice, after oxidation, is reabsorbed by the leaves after the pressure is removed. The peculiar flavor is apparently due to this and to the damp climate. Perique is now used throughout the world as an ingredient of the better kinds of pipe tobacco.
The diseases and breeding of different strains of tobacco are commercial factors of tremendous importance to the industry. With a yearly value of well over two billions of dollars, the crop is one of the most important plant products, outside of foods. The capital invested in America alone is over five hundred million dollars.
As we have seen many of our most valuable food plants are natives of and are now cultivated in temperate regions, but “sugar and spice and all things nice” mostly come from the tropics. What we usually know as spices such as nutmeg, vanilla, ginger, mace, cloves, allspice, and cinnamon are practically all confined to the tropical regions in or near the East Indies, only vanilla being of American origin. The trade in these spices has been for hundreds of years a practical monopoly in the hands of Dutch and British traders, and for hundreds of years before that the caravans from the Far East came laden with precious freight from the then mysterious country beyond the Mediterranean.
The long pods of two climbing orchids native in Central America and the West Indies furnished for many years our only supplies of this flavoring extract. But in 1891 a process of making vanilline chemically from sugar was perfected so that the vanilla trade is not what it was years ago. Vanilla planters, however, have been able to keep up the price of the plant product because of its unquestionable superiority over the manufactured article. But the latter has enormously increased the general useof vanilla, while the total plant output scarcely exceeds four hundred tons a year. Nearly all this is grown in the Old World tropics, as tropical America, where the plant is common enough as a forest orchid, has not greatly developed its culture.
In both species, known asVanilla pomponaandVanilla planifolia, the orchid has flat leaves and a fleshy climbing stem that hugs tree trunks or other supports, always in the dense shade of the tropical forests. It needs a hot moist climate, but if there be too much rain as the pods are ripening they drop off, so that only certain localities are suited to its cultivation. Various islands are apparently better suited to the plant than the mainland, Tahiti producing alone nearly half the world’s supply. The species most cultivated isVanilla planifolia, which came originally from southern Mexico, where considerable plantations are still maintained. The pods are about as thick as a thumb or finger and from five to seven inches long, and yellow when ripe. The ripening process takes several months and when completed the pod is still without the delicious fragrance for which it is famous. Curing by dipping in boiling water or by fermentation, a very delicate process requiring long experience, brings out the flavor. In some regions the pods are plunged into ashes and left there until they begin to shrivel when they are cleaned off, rubbed with olive oil, and tied at their lower end to prevent splitting. Still another process demanding that the pods be plunged in rum is followed, but only in limited degree, owing to the expense. In all of them the result is the same—that of inducing chemical changes in the pod which are responsible for its subsequent flavor.
FIG. 104.—NUTMEG (Myristica fragrans) A native of southeastern tropical Asia. The fruit, somewhat enlarged here, consists of an inner part, the nutmeg. Around this is a “splendid crimson network” which is removed by hand and forms the mace of commerce.FIG. 104.—NUTMEG(Myristica fragrans)A native of southeastern tropical Asia. The fruit, somewhat enlarged here, consists of an inner part, the nutmeg. Around this is a “splendid crimson network” which is removed by hand and forms the mace of commerce.
A native of southeastern tropical Asia. The fruit, somewhat enlarged here, consists of an inner part, the nutmeg. Around this is a “splendid crimson network” which is removed by hand and forms the mace of commerce.
A small tree of the tropical regions of eastern Asia, known asMyristica fragrans, or perhaps better asMyristica moschata, is the source of both nutmeg and mace which come from different parts of the same plant. The genus contains over one hundred species, belongs to theMyristicaceæ, and is scattered all over the Malayan region. Almost none of its relatives, however, have the fragrance of the nutmeg and none is used as a spice. Both nutmeg and mace have been known in Europe only from about 1195A.D., when in a poem about the entry of the Emperor Henry VI into Rome, the streets were described as being perfumed by the burning of nutmegs and other fragrant plants. It was not until the rise of the Dutch, who burned large stores of it at Amsterdam in 1790 in order to keep up a falling price, that nutmegs came into general use. The trees are now chiefly cultivated in the DutchEast Indies, a small fraction of the supply coming from the West Indies, which is alleged to be an inferior product.
The trees produce male and female flowers, usually on different plants, but sometimes on the same one, yellow in color and aromatic. From the females are developed the fruit which is a drupe about two inches long with a thick fleshy husk which splits upon ripening. The seed inside is the nutmeg, but from its base is an outgrowth which covers the nut with a “splendid crimson network.” This covering or network is removed by hand and forms the mace of commerce.
In the familyMyrtaceæ, which contains hundreds of plants from all over the world, mostly all shrubs and trees of tropical regions, however, there is a large genus,Eugenia. From the unopened flower buds ofEugenia caryophyllata, a small tree native only on a few islands in the Moluccas, the widely used spice known as cloves is derived. It appears to have been known to the Chinese at least two hundred years before Christ, and was regularly imported into Europe from the eighth century by caravans. Not until the Dutch began to import it by ship did it become cheap enough to have general use, but in 1609 a Dutch vessel reached England with over a hundred thousand pounds on board.
While the tree is of very local distribution, it has been introduced on a considerable scale into Penang, Zanzibar, and even to the West Indies. Trees are set out thirty feet apart each way, and in from four to eight years, depending on the locality, they begin to flower. After the full bearing stage is reached, a tree will produce from five to seven pounds ofdried cloves, an average crop being about 375 pounds to an acre. The flowers are produced in small clusters not over an inch and a half long, so that hand picking is the only method of collection. As the buds become blood red they are usually in a fit state for picking, after which they are either sun dried or, more rarely, by artificial heat. Nothing further is done to them before shipment. Zanzibar and Pemba now produce more cloves than nearly all the rest of the world put together. Oil of cloves, largely used in perfumery, is pressed out of the dried cloves.
FIG. 105.—CLOVE PLANT A native of only a few islands in the Moluccas. Cloves consist of the unopened flower buds of Eugenia caryophyllata.FIG. 105.—CLOVE PLANTA native of only a few islands in the Moluccas. Cloves consist of the unopened flower buds of Eugenia caryophyllata.
One of the commonest trees in the lowland parts of Ceylon isCinnamomum zeylanicum, a tree of the familyLauraceæ, which also contains our native sassafras. From the bark of this tree is derived cinnamon, and from a related Japanese tree,Cinnamomum Camphora, camphor is taken. Practically all theLauraceæare aromatic shrubs or trees,most of them tropical. Ceylon was occupied by the Portuguese in 1536 for the cinnamon then growing on it, which they forced the native king to supply them. Later the Dutch completely controlled the cinnamon, often burning it in Holland to keep up the price. The British, who took Ceylon in 1796, made a government monopoly of cinnamon, but subsequently turned the plantations over to private interests. The tree is now grown on an extensive scale, not only in Ceylon, but in Java and India. Ceylon still controls the cinnamon market, however.
FIG. 106.—CINNAMON A common tree of Ceylon (Cinnamomum zeylanicum). From the related Cinnamomum Camphora camphor is derived.FIG. 106.—CINNAMONA common tree of Ceylon (Cinnamomum zeylanicum). From the related Cinnamomum Camphora camphor is derived.
While the wild cinnamon trees reach considerable heights, the cultivated plants are cut so regularly that they almost always throw up a lot of young shoots from the roots, and it is the bark of these that furnishes the spice. When the bark is fit for peeling, the natives cut off the shoots, and strip the bark from them by hand, but with a specially constructedknife. After removal the bark is kept moist and in a day or two the outer skin is scraped off and the bark stretched over a stick, to form the familiar pipes or quills of cinnamon. These are graded, cut to uniform length, and after drying are ready for shipment. All of this is as yet hand work.
Other spice plants and condiments are of wide use, but can scarcely be mentioned in detail here. A few of the more important are the following:
This brief review of what the plant world provides us with in the shape of foods, beverages, fibers, drugs, rubber, spices, and tobacco, does not begin to tell us what man’s debt to plants really is. Thousands of plants, used by natives all over the world, may well provide future generations with unsuspected sources of plant products. No mention has been made of timbers nor all the forest products, except paper, which in the aggregate total an enormous sum. Perhaps no better idea of the tremendous value of plants, of the absorbing interest their utilization has always had for man, can be gained than to refer the reader to incomparably the best book on the subject, so far as tropical plants areconcerned. Sir George Watt, in his “Dictionary of the Economic Products of India,” a book of several volumes, most of which deals with plants, has left an imperishable record of man’s struggles to tame the wild plants of the forest to his needs.
A few more economic plants not yet noted are listed below, and with this our account of plants as they are used by man must close:
NOT only does the plant world furnish us with all the multitudinous products that we have already noticed, but it makes possible the beautifying of our homes and parks. For with plant materials, anyone with the knowledge and taste necessary for work of this kind may paint living landscape pictures that grow in beauty as their individual units reach maturity.
It lies outside the scope of this book to tell you the principles of design upon which such landscape pictures must be based to be really effective—that is the function of the landscape architect. But every one of us knows when a house looks and is bare of vegetation about it, and consequently has the earmarks of being merely a house, but not a home. A walk through any suburb of a large city or through most of our American villages would convince the lover of gardening that we are still miles behind England and many other countries in the love and appreciation of that kind of beauty in our home surroundings which plant life alone can furnish. How unnecessary this is anyone can see by visiting certain distinguished exceptions to the general indifference to plant life about our homes. Such suburbs as Brookline near Boston, Garden City and Morristown near New York, Guilford at Baltimore, Germantown near Philadelphia and many places on the PacificCoast show what can be done to transform an otherwise indifferent landscape into a beauty spot. While these are on the whole the homes of the wealthy, money is not what has made them, for thousands of cottage gardens in England are just as beautiful and have been made by people who live a busy industrial life, but whose desire for beautiful surroundings makes them spend their brief leisure in tending their flowers.
While large garden schemes demand somewhat expert advice as to their planning and arrangement, it is perfectly simple for anyone to begin planting his own home grounds if he has in his mind’s eye the ultimate picture which he wishes his house and garden to become. But the habits of plants, their growth requirements, their stature, and particularly their colors are so various that, with the best will in the world, a garden enthusiast without some knowledge of these things will get a wholly disappointing result. Certain plants will grow in some sections of the country, but fail in others; some flower in the south, but will not do so in the north, and a few set seeds in certain places, but never do in less favored regions. In the different sections of this chapter a few good garden plants will be noted according to the regions to which they are suited, but it must not be forgotten that some are suited also to other regions than the one in which they are listed.
Those who have read the earlier chapters already know the difference between annuals, biennials, and perennials which comprise all the herbaceous plants upon which we depend mostly for cut flowers and in large measure for giving color to the garden. The woody plants are the ones upon which mostgarden pictures depend for their permanent value—trees, shrubs and vines of infinite shape and foliage character. In the case of trees, there are two major classes, those that drop their leaves in fall and are therefore deciduous, and of value chiefly during the growing season; and the evergreens, which retain their foliage all the year and make winter landscapes of great beauty. The garden enthusiast will very soon learn that evergreen plantings, while in many ways the most beautiful, are much the most expensive and are never suited to regions near big cities, for they will not stand smoke and other fumes as many deciduous trees will do. Nor will they stand violent winds, small rainfall, and great summer heat such as characterize the central parts of the country. Their best development is therefore found east of the Mississippi and west of the Rockies, and generally speaking, their use in the garden should be confined to this region.
So much of what makes landscapes permanently beautiful depends upon trees that first place must always be given to them in any scheme of planting. The location and ultimate spread of these trees will infallibly make or mar any garden picture so that great care should be used in selecting and planting them. The actual planting details such as preparation of the soil and all the after care of plants cannot be dealt with here, but many nursery catalogues give accurate directions and there are hosts of books on the practice of gardening which give the necessary information. In listing the different trees,symbols will be put before the names, indicating in which region they are likely to grow best, as follows:
* Suited to the region east of the Mississippi and north of the frostless region of the Gulf States, but not all hardy in the northern part of United States and adjacent Canada.** Suited to the same general region, but most at home in the northern part of the area.
* Suited to the region east of the Mississippi and north of the frostless region of the Gulf States, but not all hardy in the northern part of United States and adjacent Canada.
** Suited to the same general region, but most at home in the northern part of the area.
Those that have no symbol before the name are understood to be, generally speaking, hardy throughout the country, with, of course, exceptions such as the desert and alkali regions of the country.
White Pine,Pinus Strobus.
Austrian Pine,Pinus Austriaca.
Scotch Pine,Pinus sylvestris.
Pitch Pine,Pinus rigida.
Red Pine,Pinus resinosa.
Umbrella Pine,Sciadopitys verticillata.
White Fir,Abies concolor.
Fraser’s Fir,Abies Fraseri.
Nordman’s Fir,Abies Nordmanniana.
Norway Spruce,Picea excelsa.
White Spruce,Picea alba.
Red Spruce,Picea rubens.
Koster’s Blue Spruce,Picea pungens glauca.
Engelmann’s Spruce,Picea Engelmannii.
Juniper. Different species of the genusJuniperus, mostly low growing and suitable for ground covers.
Japanese Cypress,Retinospora obtusa. There are many garden varieties.
Southern Cypress,Taxodium distichum. Not hardy in the northern part of the area. Best in wet places.
Lawson’s Cypress,Chamæcyparis Lawsoniana.
English Yew,Taxus baccata.
American Yew,Taxus canadensis.
Hemlock,Tsuga canadensis.
Of these the Austrian pine, hemlock, and the firs have the densest foliage and should be used for sucheffects. Almost nothing will grow under the evergreen trees, so close is their foliage. Lack of light and the acid leached out of their bark by rains, stop the growth of nearly all herbs underneath them.
Planted mostly for their foliage masses, but a few bear showy flowers and such will be noted. The same symbols apply.
American Beech,Fagus ferruginea.
European Beech,Fagus sylvatica.
White Oak,Quercus alba.
Red Oak,Quercus rubra, the most rapid grower of all the oaks.
Scarlet Oak,Quercus coccinea.
Horsechestnut,Aesculus Hippocastanum.
Norway Maple,Acer platanoides.
Red Maple,Acer rubrum. Prefers moist places.
Sugar Maple,Acer saccharum.
Silver Maple,Acer saccharinum. Fine tree with interesting branching, but brittle.
Tulip Tree,Liriodendron tulipifera. Showy orange-green flowers.
American Plane Tree,Platanus occidentalis. A native tree, but not so satisfactory as
Oriental Plane Tree,Platanus orientalis.
Sweet Gum,Liquidambar styraciflua.
White-leaved Poplar,Populus alba.
Balsam Poplar,Populus balsamifera.
Flowering Plum,Prunus Pissardiand many other varieties and species of the genusPrunussuch as Japanese Flowering Cherries and Plums.
American Elm,Ulmus americana.
English Elm,Ulmus campestris.
Maidenhair Tree,Ginkgo biloba. Not hardy in the northern part of the area.
Black Locust,Robinia Pseudacacia. Showy pink flowers.
European White Birch,Betula alba.
Black Alder,Alnus glutinosa.
Ash,Fraxinus americana.
Dogwood,Cornus florida. Showy white bloom. Tree will not grow well unless in partial shade.
Cornelian Cherry,Cornus Mas. Covered with yellow flowers before the leaves come out in early spring.
European Hornbeam,Carpinus Betulus.
Weeping Willow,Salix Babylonica.
Box Elder,Acer Negundo.
Magnolias. Different trees and some shrubs of the genusMagnoliaall with showy flowers. Rather tender and cannot be grown without considerable care, especially when young.
Honey Locust,Gleditsia triacanthos.
Catalpa,Catalpa speciosa. Showy flowers.
Paulownia imperialis.Showy flowers, but not hardy in northern part of the area.
There are many other deciduous and evergreen trees that might be listed and which will be found in the nursery catalogues of dealers in different parts of the country. Some of these require special conditions of soil and climate and should not be planted unless these conditions are understood. In the frostless region of the country many plants can be grown that are of tropical or near-tropical origin, but no list of them will be included here. Some of them are hardy as far north as Washington, D. C., and are worth trying by anyone living in this region, as they give us effects not possible with the trees noted.
While trees make the major feature of any garden, shrubs are chiefly used to fill in between them, or in small gardens the only woody plants that can be used are often shrubs. Within the last two or three years the Government has prohibited the importation of plants from abroad, upon the ground that various insect pests and fungous diseases were likely to be carried into the country upon such plants. For this reason American gardeners will have to propagate their own plants and we shall have touse more native plants than European and Asiatic species, which made up the bulk of our gardening material in the past.
There are excellent reasons for using native shrubs upon quite other grounds than the difficulty or danger of importing foreign ones. Native plants fit into the natural landscape better than introduced sorts, and very often the garden enthusiast can go out into the country and dig out small specimens instead of buying them.
In the list of native American shrubs given below, there are directions of where to use them, their heights, their flower color and other information about them that will help the amateur gardener to select his shrubs for definite effects. All of the shrubs listed can be gown in most parts of the country, and from the list nearly every wish of the garden planner may be gratified. This list is a practical one and has been used by landscape architects and others. It was written by the author for “The Garden Magazine” whose publishers, Doubleday, Page & Company, have kindly allowed its use here.
It will be noted that under each month group the names are arranged in botanical sequence so that allied plants are brought together. All the ninety-four species are offered for sale in American nurseries. Those in the column “Remarks and Notes” as well as about twenty others not included, must be collected in the wild.
A word now as to cultivation and care. Most of the shrubs, except those so noted, can either be planted in the spring or fall, as this is a matter that should be determined by the planter’s convenience. In digging the holes make them twice as wide anddeep as the size of the roots apparently demand. Note carefully the column “Preferred Habitat,” so that the shrubs may find congenial surroundings. Pack the soil well around the roots, water thoroughly, and frequently if the weather is dry and windy. The first winter or two a heavy mulch of leaves, or leaves and manure mixed, to be dug in the following spring, will well repay the expense and trouble.
It will be noted that some of the shrubs are marked with an asterisk (*). These all belong to the heath family and require special treatment. A soil composed of rotten sods and leafmold, about half and half, is most essential for the successful cultivation of these plants. They require peculiar acid soil conditions well approximated by the above mixture, and a mulch, preferably of red-oak leaves, or the leaves of the mountain laurel if available. Never disturb the roots of these plants by digging in the mulch, which is better left on indefinitely. Soils with much lime in them must also be avoided when growing these heath-family plants.
It is often somewhat difficult in arranging a shrubbery planting to group the plants according to the color of their flowers. For the greater ease in using the larger table, and so that one can arrive at the relative frequency of the various colors desirable for use in the scheme, the following table is appended. The numbers refer, of course, to those in the table below. The figures given in parentheses are the total of plants in each division.