Palmae
or PALMACEAE. This large order is pre-eminent, not only among monocotyledons, but in the whole world of plants, for the grandeur and beauty attained by many of the species. The order is also pre-eminently tropical in its distribution, so that, to dwellers in the cooler temperate zones, its wonderful beauty is a thing to be read of, not to be realised. Palms under glass, however spacious the accommodation allowed them, fail to impress the mind as do the same subjects in their native forests. Those who have had the pleasure of seeing these "Princes of the Vegetable Kingdom," as Linnaeus rightly styled them, in their native wilds, must feel that the impressions produced can never be effaced from the memory. While some tower, when full grown, to a height much surpassing 100ft., without emitting a leaf (e.g., Ceroxyloz andicola), the stems of others do not exceed 2ft. or 3ft. in length, and 1/4in. in thickness; others, again, have the stems so short that the leaves borne on the top of the stem rise out of the soil, and the whole plant does not exceed 3ft. in height. These dwarf Palms, however, are no less graceful than their lofty allies, and are, moreover, better known than the latter in European greenhouses, for which their dwarf stature so well fits them.
The stem is usually unbranched from the ground to the top, but in the Hyphaene thebaica it bifurcatcz several times, and it also does so in a few others. Once formed, the trunk of a Palm increases in height, but not in thickness, and it tapers upwards almost from the base. In most, the stems rise erect, or are only slightly curved; but in certain weak-stemmed genera, the stems lie on the soil, or twine among the branches of adjacent trees for support (e.g., Calamus, Desmoncus, &c.). The outer surface of the trunk in Palms is usually very hard, while the centre is soft, and consists of a mass of thin-walled cells, amid which run the woody bundles. The central mass can be easily removed, leaving a hollow tube. The leaves vary no less than the stems; but they belong to two leading forms, viz., the feather-veined, in which the chief veins of the leaf-blade arise from the sides of a long midrib (see Fig. 9), and the fan-veined, in which the midrib is so short that, at first sight, the veins all seem to arise from the top of the leaf-stalk, and to spread out like the ribs of a fan through the leaf-blade (see Fig. 10). In both forms, the blade may be undivided, except at the end, where there are always two lobes, separated by a division down to the midrib; or it may be divided partially, or down to the midrib along each side, and these segments, or pinnae, may be few (as in Fig. 11) or many (see Fig. 9), and they may themselves be divided into smaller segments, as in Caryota (see Fig. 12). In length, the leaves vary between less than 1ft. (e.g., in species of Malortiea) and a total of nearly 40ft. (as in the leaves of young plants of Maximiliana regia). The undivided lamina may, in a few species, reach a size of nearly 30ft. long by 5ft. broad (e.g., in Manicaria saccifera). The leaves in the very young plants of almost all species of Palms are undivided, except at the tip, and the species are remarkably alike, in most cases, while young.
The inflorescence assumes the form of a spadix, simple or branched, and frequently very much branched. The forms shown in Figs. 11 and 12 are of frequent occurrence. The spadix is inclosed in spathes, usually two in number; the outer, or lower, is short, and open at the tip; the inner is usually much larger, sometimes several feet long, woody or leathery, and, for a considerable time, entirely incloses the spadix. In some genera, there are from three to six spathes, only the inner of which is complete; and, in the tribe Calameae, the spathes are replaced by a large number of short, tubular, incomplete spathellae, ranged all along the peduncle and branches. The spadix always bears numerous inconspicuous flowers, which, in by far the greater number of species, are unisexual, not often hermaphrodite. Individual plants, or individual spadices in many species, are either male or female; but, in most, the same spadix bears flowers of both sexes, the females usually lower down, the males nearer the tips of the branches; or they may be associated in various ways, e.g., in Cocoinae, Geonoma, &c.; there is frequently a male flower at each side of a female, so that they stand in groups of three. They are often sunk in pits in the fleshy spadix, or they may be stalked; the flowers are almost always quite regular in structure. Frequently, the abortive male organs are found in female flowers, and vice versa. The stamens are usually six, but vary from three to very many. The ovary is typically composed of three carpels, rarely of more; but, usually, only one grows to ripeness, and only the remains of the others are left in the ripe fruits. These vary greatly. In certain groups, they resemble berries; in others, they are more like drupes, with a hard inner layer, or endocarp, as in the well-known Cocoa-nut and the Coquillanut, so often used for carved ornaments. The outer coat of the fruit is usually thin, leathery or dry, and smooth, or only bears prickles; but, in Calameae, it is covered with scales, arranged in spirals. The middle layer of the fruit (mesocarp) is usually traversed by woody bundles, which, in some, are extremely abundant, and, in others, rather few and ill-developed. In the Cocoanut, this layer is very thick and fibrous, and, from it, "coir," or fibre, for ropes, matting, &c., is prepared. In many Palms, the mesocarp contains oil in considerable quantity. The fruits of the "Oil Palm" (Elaeis guineensis) yield so much that they form a valuable export from West Africa, for use in candle-making, &c. There is usually only one ripe seed in each fruit, those in the abortive ovaries remaining undeveloped; but, occasionally, two or more may ripen. The seeds are large, but the embryo is usually small, and is sunk in a pit in the large perisperm, or albumen. This latter is white, or may be streaked with brown. In some it is fleshy (Cocoa-nut), in others horny (Date); and in the "Ivory Palms" (Phytelephas) it is so compact and hard as to be very largely used as a substitute for real ivory, in the manufacture of billiard balls and many other articles. A noteworthy peculiarity of many Palms is that they have the stems, leaves, and even the spathes and fruits, covered with sharp prickles, usually of a dark colour, which form a most efficient defence against enemies. In some kinds (e.g., Astrocaryum Jauari, &c.), the prickles on the trunk may reach a length of nearly 1ft., and a breadth, at the base, of nearly 1/2in. In certain climbing Palms (species of Calamus and Desmoncus, for instance), the prickles are hooked, or so placed as to assist the plants in climbing; but aid in this is still more efficiently given in Desmoncus and a few Chamaedoreae by certain leaflets, near the end of the leaf, being altered to form strong, recurved hooks. Palmeae are not very closely related to any other order: Juncaceae seem, on the whole, most nearly allied to them. There are from 1100 to 1200 recorded species, though a considerable number of these are not well known. They are almost confined to the tropics, extending beyond these limits in exceedingly reduced numbers. Chamaerops humilis is the only species native in Europe, where it reaches 44deg. N. Lat. The limits of latitude elsewhere are about 34deg. N. in Asia, 36deg. N. in America, 34deg. S. in Africa, 37deg. S. in S. America, in Chili, and 44deg. S. in New Zealand.
The leading genera of Palms are noticed in this work, in so far as they are of interest to gardeners; they are too numerous to be repeated here; but several of the more important genera are referred to in this article. Among the richest in species are: Astrocaryum, Attalea, Bactris, Calamus, Caryota, Chamaedorea, Cocos, Desmoncus, Geonoma, Hyphaena, Korthalsia, Licuala, Livistona, Phoenix. In addition to these, there are many genera that, despite the small number of species included in them, are of importance, either as greenhouse plants, or because of their useful products. The genera are almost confined to either the Old World or the New: Raphia, among Calameae, and Elaeis and Cocos, among Cocoinae, alone breaking this rule, out of 132 genera recognised in Bentham and Hooker's "Genera Plantarum," In each case, only one species is common to the two hemispheres. These species are Cocos nucifera (Cocoa-nut), Elaeis guineensis (Oil Palm), and Raphia vinifera. The uses of Palm-trees, and of their products, to natives of tropical lands, are far beyond what it is possible for residents in temperate regions to conceive. The stems of some supply the timber used in building houses, or the laths for forming partitions; while the tough stems, or rind of the stems, of others supply strong cordage for binding together the beams, for chair-making, and for many other household purposes. The stems of others split, and each half hollowed, make aqueducts; and of others the South American Indians make their blow-pipes for shooting out poisoned arrows. The leaves are largely used for thatch, or for walls of houses; for making fans, umbrellas, household utensils, and even tents. From the young leaves of various species fibres are largely prepared, which are used for making hammocks and other durable articles. The leaf-blades of a few are used as paper in the East; and the fibres of several species are employed in paper-making. The coarse, woody bundles that surround the stems of two American Palms are used largely for making besoms, under the name "Piassaba fibre." Two American Palms produce vegetable wax in such abundance as to be worth collecting for sale and export. In Ceroxylon andicola, the wax is formed on all parts of stem and leaves; in Copernicia cerifera, it is found only on the leaves. An Eastern Palm (Calamus draco) yields a resincus, red substance, known as "Dragon's Blood," of an astringent nature, exuded from stems and fruits. Reference has already been made to the preparation of coir from the cocoa-nut, and to the uses of Coquilla nut kernels, and of the perisperm of the Ivory-Palm, for carved ornaments, &c. As yielding food to human beings, Palms are not less valuable. The softer tissues of the interior of the stems of many trees contain large quantities of starchy stuffs, which, when prepared, form the well-known Sago. The greater part of that brought to Europe is obtained from Metroxylon laeve and M. Rumphii. The seedling plants of the Palmyra Palm (Borassus flabelliformis), and the tender tissues of the terminal bud of many Palms, are cooked and eaten in various regions of the tropics. A sweet juice, containing a large amount of sugar, is obtained from cuts in the young tissues of many Palms. When allowed to stand, the juice ferments, and forms a drink much used under the name of Palm-wine or Toddy. The fruits of several species of Palmeae afford valuable articles of food. Pre-eminent among these are the Date, either fresh or preserved, since it forms the chief food of multitudes of persons in Northern Africa. The perisperm of the Cocoa-nut forms a great part of the food of various other tropical races. Of less importance as food are the fruits of the Peach Palm, and of certain other Palms of America; but even these form a valuable resource, at times, to the native races. From the fruits and seeds of many Palms a large amount of oil can be expressed. The oil obtained from the Oil Palm, as already mentioned, is a valuable article of commerce, and that from several other species is also suitable for use, though not so abundantly produced. From the fruits of certain kinds (Elaeis melanococca, Euterpe edulis, E. oleracea, (Enocarpus Bacaba, (E. Bataua, (E. distichus, &c.), the natives of South America are accustomed to prepare a pleasantly-flavoured drink by crushing the fruits in water. Though this, also, is called Palm-wine, it contains no alcohol, if drunk, as it always is, when freshly made; but alcohol can be obtained from similar preparations of many Palm fruits, when they are allowed to ferment. But to indicate the many uses of Palms is impossible in a brief article. In conclusion, it may be mentioned that in the Tamil language of Southern Hindostan a poem exists, called "Tala vilasam," in praise of the Palmyra Palm (Borassus flabelliformis); in it 801 uses for this single species are mentioned, and, even to this number, others might easily be added. Those who desire information on this noble order of plants will find Seemann's "Popular History of Palms" serviceable as an introductory work. Martius' large and expensive "Historiae Palmarum" is still the only comprehensive work on the group; but very great additions to our knowledge have been made since it was published. Bentham and Hooker's "Genera Plantarum" is the best and most recent source of information upon the genera. The Palms of Asia have been written upon by Blume, Griffith, Scheffer, Beccari, and others; those of Australia by Muller, Wendland, and Drude; the few species from Africa by Wendland and Mann; and the American Palms by Poppig, Humboldt and Bonpland, Martius, Wendland, Grisebach, Wallace, Spruce, Trail, Im Thurm, and others. The most important work of late years on American Palms is one by Drude, in "Flora Brasiliensis," on the Palms of Brazil. Remarks on Decorative Uses, Culture, &c. The majority of Palms are by no means difficult to cultivate; yet there are a few points relating to their management which require strict attention. All of them need good drainage, and an abundant supply of water in summer; in winter, too, their roots must never approach dryness. By far the larger proportion are stove plants, and, as such, they need a considerable amount of heat, as well as moisture. One species (Trachycarpus Fortunei) is, however, hardy enough to live outside in many favourable localities all the year round; several are available for sub-tropical gardening in summer, and succeed in a warm greenhouse temperature in winter. Many others of a tenderer description may be utilised for conservatory embellishment in summer, if transferred to warmer quarters again in autumn. For exhibition, nothing is of nobler aspect than large specimen Palms; these may be most successfully cultivated in pots, or tubs, small in proportion to the size of plant. As decorative subjects for dinner tables, some of the elegant-habited Palms in a small state are indispensable, particularly the well-known and beautiful Cocos Weddeliana, than which nothing better for the purpose exists. Some of the stiffer-growing species withstand confinement in rooms and indifferent treatment remarkably well, even for a long period. Palms represent, therefore, an invaluable class of plants in gardens generally, and a selection of the most useful species is indispensable wherever plant-grouping for effect, and other phases of horticultural decorating, have frequently to be executed.
Propagation. A few Palms may be propagated from suckers where there are established plants from which such may be procured; but the general method of increase is from imported seeds. Some of these germinate in a much shorter time than others, and also grow on faster afterwards. Seeds should be sown thickly in clean, well-drained pans, and covered with about their own depth of soil; this latter should be rendered rather fine, and should consist of about two parts yellow loam and one sharp silver sand. It may be observed that the seedlings must remain, in many instances, a long time in the seed-pans; the kind of soil, and the amount of drainage are, therefore, important considerations. The pans should be plunged in, or placed immediately above, a brisk bottom heat, and kept watered, though not sufficient to cause sourness. Seeds may be sown at almost any season--early spring being that preferred. Many of the slender-growing and more delicate species may have a small portion of peat added to the loam and silver sand, as this sometimes tends to encourage root action quicker and better than when a heavier soil is used.
After-treatment. Palms always succeed better, provided proper attention is given to watering, when they are somewhat restricted at the root, than when over-potted; and this rule is applicable from the very first. When two or three leaves are formed on the seedling plants, they should be placed in the smallest-sized pots that will contain their roots without injury, and be arranged close together in a house where a high temperature and moist atmosphere are maintained. It is important at the first, and also at every subsequent potting, that no part of the stem be buried; the plant's base should merely rest on the surface of the soil, which should be rendered firm throughout by a hand rammer. Roots of Palms should never be cut, if it can possibly be avoided; indeed, with some genera, this practice would be likely to prove most disastrous. Reporting should be conducted according to the rate at which the plants progress: some grow much faster than others. The quantity of roots may be taken as a guide; if these are not more or less crowded, the operation of re-potting may be deferred, as a rule, until they are. Established plants, of any size, should be overhauled in early spring, and any necessary shifting done. If roots are found to have become matted near the base, the old crocks should, if possible, be removed, and soil afterwards substituted. The ball should then be placed intact in another pot, where there is a space of about 2in. all round; this will often suffice for the next two years, at least. When repotting is unnecessary, a light top-dressing may be given instead. It is essential that the ball should be in a proper condition regarding moisture, at the time of repotting, whether of small or large specimens. In a young state, the smallest shifts are recommended, consistent with the rate of progress made by the plants. In houses of large dimensions, Palms may be planted out; at least, those which are calculated to attain a great height, and are expected to be otherwise proportionately large when developed. For a conservatory, of course, only a few will succeed all the year round; yet these should be utilised for specimens in some part of the beds. The main points in the successful culture of Palms so treated, are much the same as if they were in pots, namely, good drainage and plenty of water. In summer, syringing morning and evening may be freely practised; in winter, the moisture from evaporation, caused by damping the floor and stages, will usually be found sufficient. As Palms have to remain, perhaps, many years in the same soil, it is important that only such as is suitable should be used. Some authorities recommend equal proportions of loam, vegetable mould, peat, and sand, as a general compost. Anything tending to decay, except very slowly indeed, should not be used, as, possibly, it might kill, rather than encourage, the roots. Peat is not altogether a necessity for established Palms; in yellow loam, with plenty of sand, and some charcoal intermixed, they will grow well, and make firmer, yet, perhaps, somewhat slower growth, which is, of the two, more desirable. Manure water is of great assistance to Palms when their roots are somewhat restricted, provided the plants are in good health. It should be made from cow-manure and soot, which imparts a healthy appearance to the leaves. Some information on culture, and references to the uses for which various Palms are best suited, will be found under all the more important genera included in Palmeoe throughout this work.