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Information on Palm history and anatomy follows. However, all Palms and plants must be placed in an environment that meets their basic requirements and this information is at: Basic Palm Trees Needs.
I advise you to review the Palm Tree Care Resources available on the SPT site along with reading this information on palms.
Palms history and a brief
bit of Palms anatomy
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Palm Tree - Information
Worldwide, the family Palmae (Palm
Tree) is composed of over 230 genera and about 3000 species. Only
a few of these are indigenous to the continental United States, and most
of these are restricted to the warmer regions of southern United States,
southern Florida and southern California. However, a large number
of exotic species have been imported for ornamental purposes and a few
of these have become widely naturalized.
Evolution
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A cross-section of a palm branch Arecaceae is the first modern family of monocots that is clearly represented in the fossil record. Palms first appear in the fossil record around 80 million years ago, during the late Cretaceous Period. The first modern species, such as Nypa fruticans and Acrocomia aculeata, appeared 69-70 million years ago, confirmed by fossil Nypa pollen dated to 70 million years ago. Palms appear to have undergone an early period of adaptive radiation. By 60 million years ago, many of the modern, specialized genera of palms appeared and became widespread and common, much more widespread than their range today. Because palms separated from the monocots earlier than other families, they developed more intrafamilial specialization and diversity. By tracing back these diverse characteristics of palms to the basic structures of monocots, palms may be valuable in studying monocot evolution.[12]
Evidence can also be found in samples of petrified palmwood.
Palms, for identification
purposes. can be divided into two major groups: those that have palmate
or fan-shaped leaves; and those that have pinnate, or feather-shaped
leaves.
The palmate-leaved species are characterized by a
leaf structure in which all leaf segments arise from a single point, similar
to the structure of a human hand. Pinnate leaves are characterized
by leaves along each side of a central axis, similar in design to that
of a feather.
Palm Tree (Palmaceae) have been termed the princes
of the vegetable kingdom. Neither the anatomy of
the Palms stems nor the conformation of Palm
Tree flowers, however, entitles them to any such
high position in the vegetable hierarchy. Palm Tree
stems are not more
complicated in structure than those of the common
butcher’s broom
(Ruscus); their flowers are for the most part as
simple as those of a rush (Juncus). The order Palmaceae
is characterized among monocotyledonous plants by
the presence of an unbranched stem bearing a tuft
of leaves at the extremity only, or with the leaves
scattered; these leaves, often gigantic in size,
being usually firm in texture and branching in a
pinnate or palmate fashion. The flowers are 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 pistil of 1-3 carpel's,
each with a single ovule and a succulent or dry fruit.
The seed consists almost exclusively of endosperm,
Upper portion of Coconut seed, albumen in a cavity
in showing the embryo, embedded in endosperm, which
is lodged the relatively very minute embryo. These
are the general characteristics by which this very
well-defined order may be discriminated, but, in
a group containing considerably more than a thousand
species, Palm Tree deviations from the general 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.
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Palm Tree - Stems
Taking the stem first,
we may mention that it is in very many palms
relatively tall, erect, unbranched, regularly
cylindrical, or dilated below so as to form an
elongated cone, either smooth, or covered with
the projecting remnants of the former Palms
leaves, or marked with circular scars indicating
the position of those leaves which have now fallen
away. It varies in. diameter from the thickness
of a reed (as in Chamaedorea) to a sturdy pillar-like
structure as seen in the date-palm, Palmyra palm
or Talipot. In other cases the very slender Palm
Tree stem is prostrate, scandent by means of
formidable hooked prickles which, by enabling
the plant to support itself on. The branches
of neighboring Palms, also permit the stem
to grow to a very great length and so to expose
the foliage to the light and air above the tree-tops
of the dense forests the Palm Tree grows in,
as in the genus Calamus, the Rattan or Cane palms.
In some few instances the trunk, or that portion
of it which is above ground, is so short that
the Palm Tree is in a loose way called
“ stemless “ or “ acaulescent,” as in Geonoma,
and as happens sometimes in the only species found
in a wild state in Europe, Chamaerops humus. The
vegetable ivory (Phytelephas) of equatorial America
has a very short thick stem bearing a tall cluster
of leaves which appears to rise from the ground.
In many Palm Tree species the trunk is covered with
a dense network of stiff fibers, often compacted
together at the free ends into spines. This fibrous
material, which
is so valuable for cordage, consists of the fibrous
tissue of the leafstalk, which in these cases persists
after the decay of the softer portions. It is very
characteristic of some palms to produce from the
base of the stem a series of adventitious roots which
gradually thrust themselves into the soil and serve
to steady the Palm tree and prevent its overthrow
by the wind. The underground stem of some species,
e.g. of Calamus, is a rhizome, or root-stock, lengthening
in a more or less 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
Palm Tree stem above ground is unusual, except in
the case of the Doum palm of Egypt (Hyphaene) , where
the stem forks, often repeatedly; this is due to
the development of a branch to an equal strength
with the main stem. In other cases branching, when
present, is probably the result of some injury to
the terminal bud at the top of the stem, in consequence of which
buds sprout out from below the apex.
The internal structure of the
Palm Tree 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 skeleton but
also to the fact that, as growth goes on, the
originally soft cellular ground tissue through
which the fibers run becomes hardened by the
deposit of woody matter within the cells, so
that ultimately the cellular portions of the
Palm Tree become as hard as the woody fibrous
tissue.
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Palm Tree Types - Leaves Information
The leaves of the Palms are
either arranged at more or less distant intervals
along the stem, as in the canes, or are approximated
in tufts at the end of the stem, thus forming
those noble crowns of foliage which are so closely
associated with the general idea of a palm. In
the young condition, while still unfolded, these
Palm leaves, with the succulent end of the stem
from which they arise, form “the cabbage,” which
in some Palm species is highly esteemed as an
article of food.
The adult Palms leaf generally
presents a sheathing base tapering upwards into
the stalk or petiole, and this again bearing
the lamina or blade. The sheath and the petiole
very often bear stout spines, as in the rattan
palms and when, in course of time, the upper
parts of the leaf decay and fall off, the base
of thePalms leaf-stalk and sheath often
remain, either
entirely or in their fibrous portions only, which
latter constitute the investment to the Palms 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 I , may be measured in tens of feet.
In form the Palm Tree leaves are very
rarely simple; usually they are more or less
divided, sometimes, as in Caryota, extremely
so. In Palm tree species of Geonoma, Vers chaffeltia
and some others, the leaf splits into two divisions
at the apex and not elsewhere; but more usually
the leaves branch regularly. The form of the
segments is generally more or less linear, but
a very distinct appearance is given by the broad
wedge-shaped leaflets of such palms as Caryotct,
Martinezia or Mauritia. These forms run one into
another by transitional gradations; and even
in the same palm tree 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 Palms 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 surface is of a glaucous white or bluish
color, from a coating of wax.
The inflorescence of the
palm tree 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
“. These parts may be small, or they may attain relatively enormous
dimensions, hanging down from amid the Palm Tree
crown of foliage like huge tresses, and adding greatly
to the noble effect of the tree's 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 Palms then develops a huge inflorescence,
and after the fruit has ripened, the Palm tree dies.
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Palm Tree - Flowers
The individual Palms flowers are usually small (figs.
3, 6), greenish and insignificant; their general
structure has been mentioned already. Modifications
from the Palm Tree typical structure arise from difference
of texture, and specially from suppression of parts,
in consequence of which the Palm flowers are very
generally unisexual, though the flowers of the two
sexes are generally produced on the same Palm tree
(monoecious), not indeed always in the same season,
for a Palm tree in one year may produce all male
flowers and in the next all female flowers. Sometimes the Palms 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 carpel's 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 for
the Palms, the pollen has to be transported by
the agency of the wind or of insects to the Palm
Tree's 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 travelers speak of the date palms of Egypt (Phoenix
dactylifera) being at
daybreak hidden in a mist of pollen grains. In other
Palm tree cases fertilization is effected by the
agency of 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
carpel's
with their ovules may become absorbed, as in the
coco-nut, the fruit of which contains only one seed
though the three carpel's
are indicated by the three longitudinal sutures and
by the presence of three germ-pores on the hard endocarp.
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Palm Tree - Fruit
The Palms fruit is various in form, size and character;
sometimes, as in the common date from a Palm Tree
is a berry with a fleshy rind enclosing a hard stony
kernel, the true seed; the fruit of Areca is similar;
sometimes it is a kind of drupe as in Acrccomia,
or the coconut, Cocos nucif era, where the fibrous
central portion investing the hard shell corresponds
to the fleshy portion of a plum or cherry, while
the shell or nut corresponds to the stone of stone-fruits,
the seed being the kernel. In Borassus the three
seeds are each enclosed in a separate chamber formed
by the stony endocarp. Sometimes, as in the Palm
Tree species of Metroxylon, Raphia, and Daemonorops,
the Palms fruit is covered with hard, pointed,
reflexed shining scales, which give the Palm a very
remarkable appearance.
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Palm Tree - Seeds
The Palm tree seeds show a corresponding variety in
size and shape, but always consist of a mass of Palm endosperm, in which
is embedded a relatively very minute embryo. The hard stone of the date
palm 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 Palms genera the
inner seed coat becomes thickened along the course of the vascular bundles
and growing into the endosperm produces the characteristic appearance
in section known as ruminate—this is well shown in the Areca nut.
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Palm Tree - Family
The order (Palm Tree) contains 32 genera with about
1100 species mainly tropical, but with some Palms
in warm temperate regions. Chamaerops humilis is
a native of the Mediterranean region, and the date-palm
yields fruit in southern Europe as far north as 38° N. latitude.
In eastern Asia the Palms, like other tropical
families, extend along the coast reaching Korea and
the south of Japan. In America a few small
genera occur in the southern United States and California;
and in South America the southern limit is reached
in the Chilean genus Juhaea (the Chile coco-nut)
at 37° S. latitude.
The great centers of distribution for Palm Trees
are tropical America and tropical Asia; tropical
Africa contains only 2 genera, though some of the
species, like the Doum Palm Tree (Hyphaene thebaica)
and the Deleb or Palmyra palm tree(Borassusfiabellifer)
have a wide distribution. With three exceptions Old
and New World forms are distinct—the coco-nut
(Cocos nucifera) is widely distributed on the coasts
of tropical Africa, in India and the South Seas,
the other species of the genus Palm are confined
to the western hemisphere. The oil palm tree (Elaeis
guineensis) is a native of west tropical Africa,
the other Palm Tree species of the genus is tropical
American. Raphia has also species in both tropical
Africa and tropical America.
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Palm Tree
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