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PALM (Lat. palma, Gr. iraX6.jn )

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Originally appearing in Volume V20, Page 642 of the 1911 Encyclopedia Britannica.
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PALM (See also:Lat. See also:palma, Gr. iraX6.jn )  , originally the See also:flat of the See also:hand, in which sense it is still used; from this sense the word was transferred as a name of the trees described below . The emblematic use of the word (= See also:prize, See also:honour) represents a further transference from the employment of the See also:palm-leaves as symbols of victory . The Palms (Palmaceae) have been termed the princes of the See also:vegetable See also:kingdom . Neither the See also:anatomy of their stems nor the conformation of their See also:flowers, however, entitles them to any such high position in the vegetable See also:hierarchy . Their stems are not more complicated in structure than those of the See also:common See also:butcher's See also:broom (Ruscus); their flowers are for the most See also:part as See also:simple as those of a See also:rush (Juncus) . The See also:order Palmaceae is characterized among monocotyledonous See also:plants by the presence of an unbranched See also:stem bearing a tuft of leaves at the extremity only, or with the leaves scattered; these leaves, often gigantic in.See also:size, being usually See also:firm in texture and branching in a pinnate or palmate See also:fashion . The flowers are See also:borne on simple or branching spikes, very generally protected by a spathe or spathes, and each consists typically of a perianth of six greenish, somewhat inconspicuous segments in two rows, with six stamens, or See also:pistil of 1-3 carpels, each with a single ovule and a succulent or dry See also:fruit, never dehiscent (fig. r, A and B) . The See also:seed consists almost exclusively of endosperm or albumen in a cavity in which is lodged the relatively very See also:minute embryo (fig. r, C) . These are the See also:general characteristics by which this very well-defined order may be discriminated, but, in a See also:group containing considerably more than a thousand See also:species, deviations from the general See also:plan of structure occur with some frequency . As the characteristic appearances of palms depend to a large extent upon these modifications, some of the more important among them may briefly be noticed . Taking the stem first, we may mention that it is in very many palms relatively tall, erect, unbranched, regularly cylindrical, Fin . 2.—Daemonorops See also:Draco (a Rattan Palm) .

r, See also:

Young shoot much reduced . 2, Part of stem bearing male inflorescence . 3, Part of See also:female inflorescence . 4, The same bearing ripe fruits . or dilated below so as to See also:form an elongated See also:cone, either smooth, or covered with the projecting remnants of the former leaves, or marked with circular scars indicating the position of those leaves which have now fallen away . It varies in See also:diameter from the thickness of a See also:reed (as in Chamaedorea) to a sturdy See also:pillar-like structure as seen in. the date-palm, See also:Palmyra palm (fig . 7) or Talipot . In other cases the very slender stem is prostrate, or en (After See also:Bentley and Trimen, Medicinal Plants, by permission of Messrs J . & A . See also:Churchill.) Fin . 3.-Areca Palm (Areca See also:Catechu) . r, See also:Tree, very much reduced .

5, Male See also:

flower opened by removal 2, Part of See also:leaf. of a petal . 3, Portion of inflorescence with 6, Fruit . male flowers above, female 7, 8, Same cut across,and length- (larger) below. See also:wise. p, Fibrous pericarp; 4, Petal of a male flower. en, ruminated endosperm ; e, embryo . scandent by means of formidable hooked prickles which, by enabling the plant to support itself on the branches of neighbouring trees, also permit the stem to grow to a very See also:great length and so to expose the foliage to the See also:light and See also:air above the tree-tops of the dense forests these palms grow in, as in the genus Calamus, the Rattan or See also:Cane palms . In some few instances the See also:trunk, or that portion of it which is above ground, is so See also:short that the plant is in a loose way called " stemless " or " See also:acaulescent," as in Geonoma, and as happens sometimes in the only species found in a See also:wild See also:state in See also:Europe, Chamaerops humilis . The vegetable See also:ivory (Phytelephas) of See also:equatorial See also:America has a very short thick stem bearing a tall cluster of leaves which appears to rise from the ground . In many species the trunk is covered with a dense network of stiff See also:fibres, often compacted together at the See also:free ends into spines . This fibrous material, which is so valuable for cordage, consists of the fibrous See also:tissue of the leaf-stalk, which in these cases persists after the decay of the softer portions . It is very characteristic of some palms to produce from the See also:base of the stem a See also:series of See also:adventitious roots which gradually thrust themselves into the See also:soil and serve to steady the tree and prevent its overthrow by the See also:wind . The underground stem of some species, e.g. of Calamus, is a rhizome, or See also:root-stock, lengthening in a more or less See also:horizontal manner by the development of the terminal bud, and sending up lateral branches like suckers from the root-stock, which form dense thickets of cane-like stems . The branching of the stem above ground is unusual, except in the See also:case of the Doum palm of See also:Egypt (Hyphaene), where the stem forks, often repeatedly; this is due to the development of a See also:branch to an equal strength with the See also:main stem . In other C FiG.r;A,B .

—Floral diagrams of a Palm (Chamaerops hurnilis) . A, male flower . B, female-flower . C, Upper portion of Coco-See also:

nut seed, showing e, embryo, embedded in a, endosperm . cases branching, when See also:present, is probably the result of some injury to the terminal bud at the See also:top of the stem, in consequence of which buds sprout out from below the See also:apex . The See also:internal structure of the stem does not differ fundamentally from that•of a typical monocotyledonous stem, the taller, harder trunks owing their hardness not only to the fibrous or woody See also:skeleton but also to the fact that, as growth goes on, the originally soft cellular ground tissue through which the fibres run becomes hardened by the See also:deposit of woody See also:matter within the cells, so that ultimately the cellular portions become as hard as the woody fibrous tissue . The leaves of palms are either arranged at more or less distant intervals along the stem, as in the canes (Calamus, Daemonorops, fig . 2, &c.), or are approximated in tufts at the end of the stem, thus forming those See also:noble crowns of foliage (See also:figs . 5, 6, 7) which are so closely associated with the general See also:idea of a palm . In the young See also:condition, while still unfolded, these leaves, with the succulent end of the stem from which they arise, form " the See also:cabbage," which in some species is highly esteemed as an See also:article of See also:food . The adult leaf very generally presents a sheathing base See also:taper- See also:ing upwards into the stalk or petiole, and this again bearing the lamina or blade . The sheath and the petiole very often See also:bear stout spines, as in the rattan palms (see fig .

2); and when, in course of See also:

time, the upper parts of the leaf decay and fall off, the base of the leaf-stalk and sheath often remain, either entirely or in their fibrous portions only, which latter constitute the investment to the stem already mentioned . In size the leaves vary within very wide limits, some being only a few inches in extent, while those of the noble Carycta may be measured in tens of feet . In form the leaves of palms are very rarely simple; usually they are more or less divided, sometimes, as in Cayyota, extremely so . In species of Geonoma, Vers- chaleltia and some others, the leaf splits into two divisions at the apex and not I, Fruit of date-palm (See also:Phoenix the leaves branch regularly dactylifera), nat. size . 2, Same cut lengthwise showing in a palmate fashion as in seed s. the See also:fan - palms Latania, Borassus (fig . 7), Chamaerops, Sabal, &c., or in a pinnate fashion as in the See also:feather-palms, Areca (fig . 3), Kentia, Calamus, Daemonorops (fig . 2), &c . The form of the segments is generally more or less linear, but a very distinct See also:appearance is given by the broad See also:wedge-shaped leaflets of such palms as Cayyota, Martinezia or Mauritia . These forms run one into another by transitional gradations; and even in the same palm the form of the leaf is often very different at different stages of its growth, so that it is a difficult matter to name correctly seedling or juvenile palms in the condition in which we generally meet with them in the nurseries, or even to foresee what the future development of the plant is likely to be . Like the other parts of the plant, the leaves are sometimes invested with hairs or spines; and, in some instances, as in the magnificent Ceroxylon andicola, the under See also:surface is of a See also:glaucous See also:white or bluish See also:colour, from a coating of See also:wax . The inflorescence of palms consists generally of a fleshy spike, either simple or much branched, studded with numerous, sometimes extremely numerous, flowers, and enveloped by one or more sheathing bracts called " spathes " (fig .

Phoenix-squares

5) . These parts may be small, or they may attain relatively enormous dimensions, See also:

hanging down from amid the See also:crown of foliage like huge tresses, and adding greatly to the noble effect of the leaves . In some cases, as in the Talipot palm, the tree only flowers once; it grows for many years until it has become a large tree then develops a huge inflorescence, and after the fruit has ripened, See also:dies . The individual flowers are usually small (figs . 3, 6), greenish and insignificant; their general structure has been mentioned already . Modifications from the typical structure arise from difference of XX . 2Itexture, and specially from suppression of parts, in consequence of which the flowers are very generally unisexual (figs . I, 3, 6), though the flowers of the two sexes are generally produced on the same tree (monoecious), not indeed always in the same See also:season, for a tree in sp, Spathe enveloping the fruits, 3, The same cut lengthwise . shown on a larger See also:scale in I. m, Fibrous mesocarp; en, 2, A fruit. hard endocarp; s, seed . one See also:year may produce all male flowers and in the next all female flowers . Sometimes the flowers are modified by an increase in the number of parts; thus the usually six stamens may be represented by I2•to 24 or even by hundreds . The carpels are usually three in number, and more or less combined; but they may be free, and their number may be reduced to two or even one .

In any case each carpel contains but a single ovule . Owing to the sexual arrangements before mentioned, the See also:

pollen has to be transported by the agency of the wind or of See also:insects to the female flowers . This is facilitated sometimes by the elastic movements of the stamens and anthers, which liberate the pollen so freely at certain times that travellers speak of the date-palms of Egypt (Phoenix dactylifera) being 'at daybreak hidden in a mist of pollen grains . In other cases fertilization is effected by the agency of See also:man, who removes the male flowers and scatters the pollen over the fruit-bearing trees . This practice has been followed in the case of the date from time immemorial; and it afforded one of the earliest and most irrefragable proofs by means of which the sexuality of plants was finally established . In the course of ripening of the fruit two of the carpels with their ovules may become absorbed, as in the coco-nut, the fruit of which contains only one seed though the three carpels are indicated by the three See also:longitudinal sutures and by the presence of three germ-pores on the hard endocarp . The fruit is various in form, size and See also:character; sometimes, as in the common date (fig . 4) it is a See also:berry with a fleshy rind enclosing a hard stony See also:kernel, the true seed; the fruit of Areal (fig . 3) is similar; sometimes it is a See also:kind of drupe as in Acrccomia (fig . 5), or the coconut, Cocos nucif era, where the fibrous central portion investing the hard See also:shell corresponds to the fleshy portion of a See also:plum or See also:cherry, while the shell or nut corresponds to the See also:stone of stone-fruits, the seed being the kernel . In Borassus the three seeds are each enclosed in a See also:separate chamber formed by the stony endocarp (fig . 7) .

Sometimes, as in the species of Metroxylon (fig . 6), Raphia, Daemonorops (fig . 2), &c., the fruit is covered with hard, pointed, reflexed shining scales, which give it a very remarkable appearance . The seeds show a corresponding variety in size and shape, but II always consist of a See also:

mass of endosperm, in which is embedded a relatively very minute embryo (figs. t, 3, 6) . The hard stone of the date is the endosperm, the white oily flesh of the coco-nut is the same substance in a softer condition; the so-called " vegetable ivory " is derived from the endosperm of Phytelephas . In some genera the inner seed coat becomes thickened along the course of the vascular bundles and growing into the endosperm produces the characteristic appearance in See also:section known as ruminate—this is well shown in the Areca nut (fig . 3) . 1, Apex of leaf . 6, Fruit . 2, Branchlet of fruiting spadix . 7, Fruit cut lengthwise, showing 3, Branchlet of male inflorescence. seed s and the minute em- 4, Spike of male flowers. bryo e which is embedded in 5, Same cut lengthwise. a horny endosperm . The order contains 132 genera with about i See also:loo species mainly tropical, but with some representatives in warm temperate regions .

Chamaerops humilis is a native of the Mediterranean region, and the date-palm yields fruit in See also:

southern See also:Europa as far See also:north as 38° N. See also:latitude . In eastern See also:Asia the Palms, like other tropical families, extend along the See also:coast reaching See also:Korea and the See also:south of See also:Japan . In America a few small genera occur in the southern See also:United States and See also:California; and in South America the southern limit is reached in the Chilean genus Jubaea (the See also:Chile coco-nut) at 370 S. latitude . The great centres of See also:distribution are tropical America and tropical Asia; tropical See also:Africa contains only 11 genera, though some of the species, like the Doum palm (Hyphaene thebaica) and the Deleb or Palmyra palm (Borassus flabellifer) have a wide distribution . With three exceptions Old and New See also:World forms are distinct—the coco-nut (Cocos nucifera) is widely distributed on the coasts of tropical Africa, in See also:India and the South Seas, the other species of the genus are confined to the western hemisphere . The oil palm (Elaeis guineensis) is a native of See also:west tropical Africa, the other species of the genus is tropical See also:American . Raphia has also species in both tropical Africa and tropical America . The 132 genera of the order are ranged under seven tribes, distinguished by the nature of the foliage, the sexual conditions of the flower, the character of the seed, the position of the raphe, &c . Other characters serving to distinguish the See also:minor See also:groups are afforded by the See also:habit, the position of the spathes, the " See also:aestivation " of the flower, the nature of the stigma, the ovary, fruit, &c . It is impossible to overestimate the utility of palms . They furnish food, shelter, clothing, See also:timber, See also:fuel, See also:building materials,sticks, fibre, See also:paper, See also:starch, See also:sugar, oil, wax, See also:wine, See also:tannin, See also:dyeing materials, See also:resin and a See also:host of minor products, which render them most valuable to the natives and to tropical agriculturists . The Coco-nut palm, Cocos nucifera, and the Date palm, Phoenix dactylifera, have been treated under separate headings .

Sugar and liquids capable of becoming fermented are produced by Caryota urens, 1, Portion of female inflorescence showing young fruits . 2, Fruit cut across showing the three seeds, all much reduced . Cocos nucifera, Borassus flabellifer, Rhapis vinifera, Arenga saccharifera, Phoenix silvestris, Mauritia vinifera, &c . Starch is procured in abundance from the stem of the See also:

Sago palm, Metroxylon (fig . 6) and others . The fleshy mesocarp of the fruit of Elaeis guineensis of western tropical Africa yields, when crushed and boiled, " palm oil." Coco-nut oil is extracted from the oily endosperm of the coconut . Wax is exuded from the stem of Ceroxylon andicola and Copernicia cerifera . A variety of " See also:dragon's See also:blood," a resin, is procured from Daemonorops Draco and other species . Edible fruits are yielded by the date, the See also:staple food of some districts of See also:northern Africa . The coco-nut is a source of See also:wealth to its possessors; and many of the species, e.g . Areca sapida (Cabbage-palm and others), are valued for their " cabbage "; but, as this is the terminal bud whose removal causes the destruction of the tree, this is a wasteful article of See also:diet unless care be taken by judicious planting to avert the annihilation of the supplies . The famous " Coco de mer," or See also:double coco-nut, whose floating nuts are the See also:objects of so many legends and superstitions, is known to See also:science as Lodoicea seychellarum .

The tree is See also:

peculiar to the See also:Seychelles, where it is used for many useful purposes . Its fruit is like a huge plum, containing a stone or nut like two coco-nuts (in their husks) united together . These illustrations must suffice to indicate the numerous economic uses of palms . The only species that can be cultivated in the open air in See also:England, and then only under exceptionally favourable circumstances, are the-See also:European Fan palm, Chamaerops humilis, the See also:Chusan palm, Trachycarpus Fortunei, &c., and the Chilean Jubaea spectabilis . The date palm is commonly planted along the Mediterranean coast . There are several See also:low growing palms, such as Rhapis flabelliformis, Chamaerops humilis, &c., which are suited for See also:ordinary See also:green-See also:house culture, and many of which, from the thick texture of their leaves, are enabled to resist the dry and often See also:gas-laden See also:atmosphere of living rooms .

End of Article: PALM (Lat. palma, Gr. iraX6.jn )
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