Plants

Palm trees have been called the princes of the vegetable kingdom. Neither the anatomy of the Palm tree stems nor the conformation of their flowers, however, entitles them to any such high position in the vegetable hierarchy. 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 huge 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 made up of 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 is made up of 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, 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.

The leaves of 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, which causes them to form 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 leaves, with the succulent end of the stem from which they arise, form “the cabbage,” which in some species is highly esteemed as an article of food.

The adult leaf very 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 the leaf-stalk and sheath often remain, either entirely or in their fibrous portions only, which latter constitute the investment to the stem.

The individual flowers are usually small, greenish and insignificant; their general structure has been mentioned already. Modifications from the typical structure arise from difference of texture, and specially from suppression of parts, in consequence of which the flowers are very generally unisexual, though the flowers of the two sexes are generally produced on the same tree, not indeed always in the same season, for a tree in one 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 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. The pollen has to be transported by the agency of the wind or of 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 travelers speak of the date-palms of Egypt being ‘at daybreak hidden in a mist of pollen grains. In other 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.

The Palm tree fruit is various in form, size and character; sometimes, as in the common date it 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.