Part 14

Every square inch, then, of this sackcloth tells of the lapse of time; these horse-hair-like fibres were once green and vascular, enclosing a soft pulp; in short, they were a part of a verdant leaf; the reduction of each congeries of veins to this condition was a work of time, and this has been effected by many leaf-bases in succession.

An examination of this gomuti, as it is called, does not indeed help us to identify the actual interval lapsed in the history of the plant; but we may arrive at this from other considerations. The great sheathing bases themselves remain in numbers attached to the upper portion of the stem, though the greater portion of the midrib with the pinnae has decayed and fallen; and in the lower part, where even the bases have disappeared, still broad lateral scars are left, marking off the stipe into horizontal rings, which are not less conclusively certain evidences of the former existence of similar bases, and therefore, still earlier, of leaves.

The Sugar Palm developes and matures on an average six leaves every year. On counting the dry leaf-bases, and the scars, I find on this trunk, a hundred and twenty: besides which there are about a dozen expanded leaves, and two visible, which are not unfolded. A hundred and thirty-four leaves then have left proofs of their existence here; which divided by six, gives about twenty-two years as the age of this Palm. This is the age of this tree, however, since it began to form a stem; but several years of infancy must be added to the sum, during which its fronds sprang in succession from the surface of the soil.

Look at this Areca. By-and-by it will grow to the loftiest stature attained by any of its tribe, and its noble crown of leaves will wave on the summit of a slender pillar a hundred and fifty feet in height. But at present it has no stem at all; the widely arching leaves diverge from a central point which is below the surface of the soil. Here, then, are no dead leaf-bases; here are no old historical scars:--have we any evidence of past time here? Yes, surely. See this fully developed leaf. It is composed of a stout midrib, along the two opposite edges of which grow, like the beards of a feather, narrow sword-like leaflets, separated from each other by intervals of about two inches. But this pinnate condition,--which is so inseparable from the developed leaf of a great division of the Palm tribe, that our idea of a palm-leaf almost always is that of an enormous feather,--is by no means the original state. Observe this young leaf which is not yet thoroughly expanded; the leaflets are, indeed, separated everywhere, except that the tips of all are connected by a very narrow ribbon of the common green lamina, which runs from one to another. In the fully opened leaves, this has been torn apart and is not distinguishable.

But, let us carefully open this still younger leaf, which is protruding like a thin green rod, or rather like a closed fan, from the centre of the crown. We must handle it delicately, for it is very tender. Now you see it is not pinnate at all; the leaf is as entire as a Musa leaf, which, indeed, it much resembles, except that each half is folded transversely, and then these transverse folds are packed one on another longitudinally, fan-fashion. Each of the transverse folds answers to a future leaflet. It is the development of the midrib in length that tears asunder the divisions of the lamina, and converts them into separate, and by-and-by remote, pinnae.

It is manifest then that every leaflet on the midrib of a pinnate-leaved Palm is a record of past time, as real as the leaf-bases on the trunk, inasmuch as, in each case, there is ocular proof that the conditions of existence are different from what they have been. And yet in this case, the evidences are fallacious, since the Areca before us has even now been created.

Here is an extraordinary plant. Though no thicker than your little finger, it will be found almost a quarter of a mile in length. This is a kind of Cane (Calamus); its slender jointed and polished stem is encased in the closely-sheathing and tubular bases of the leaves, which are spiny on their midribs, spiny on their pinnae, and horridly spiny on the long and tough whip-lash in which the point of each leaf terminates. This lengthened cord is studded, at intervals of a few inches, with whorls of stout and acute prickles which are hooked backwards, and performs an important part in the economy of the plant. We see how it sprawls along the ground a few yards, then climbs up a tall tree, runs over the summit, descends on the opposite side to the ground, mounts over another tree, and thus pursues its wormlike course. Now as the pinnate leaves are put forth at every joint, the formidably armed flagellum affords a secure holdfast to the climbing stem, which otherwise would be liable to be blown prostrate by the first gust of wind; the recurved hooks, however, catch in the leaves and twigs of the trees, and effectually maintain the domination of the prickly intruder.

It is obvious that every inch sprawled over by this trailing stem supposes all the previous inches of its lengthening course; that every successive joint implies the existence of all the earlier joints; that every whorl of spines involves the development of every former whorl. Yet our reasoning is at fault; there has been as yet no succession; the development has been simultaneous, for it is the development, not of growth, but of creation.

Enough of Palms. Look at this Agave. Its thick, fleshy, glaucous leaves, with spinous margins and pointed ends, are arranged in many whorls on the summit of a stem, which is scarcely visible, as it barely rises above the soil. From the centre of the crown springs the stately flower-stalk, itself a tree of forty feet in stature, having a cluster of yellow blossoms at the extremities of its candelabra-like branches.

Have we here any clue to the past history of the plant? The tall flower-stalk, it is true, is of rapid growth, its whole stature having been attained within three or four weeks. But those massive leaves! Each of these lasts many years, and their development is as slow as that of the flower-stalk is rapid. Certainly we cannot assign to this individual, in the very vigour of its inflorescence, an antiquity less than half a century, and perhaps it may be considerably more.

You are altogether wrong; for it is but just called into existence.

We pass on, and pause before a noble example of one of the stateliest of plants,--the Traveller's Tree (Urania speciosa). It is a great Musaceous plant, resembling one of those fans which in the Southern States of America are made by ladies out of the broad tail-feathers of a turkey. Its leaves, of vast size, consist of a broad oblong lamina of the most brilliant green hue, divided equally by a midrib which descends in a smooth cylindrical petiole, much longer than the lamina (which is itself eight feet or more in length). Each leaf-stalk terminates below in a great demi-sheath, out of which springs another, in a zigzag or distichous fashion, the whole diverging, as they rise, in the same plane.

Below the alternately-sheathing leaves, of which there are but eight at present existing, there are the bases of others, now dead, which, when alive, evidently followed the same arrangement; and these give place yet lower to rings, each partly surrounding a massive conical stem.

I fear we have no criterion for determining the exact age of such a plant as this from actual observations on its rate of growth. From the fewness of its existing leaves they probably endure a considerable time; but at all events here are indubitable evidences of successive generations of leaves which are now past and gone; some of which are represented by withered rib-bases, while older ones have left but the scars which indicate the positions on the trunk where once they stood. Here are distinct testimonies to the lapse of a considerable period of time since the magnificent Urania, began its existence. Yet we should err egregiously by giving credence to them, since these developments are all prochronic.

"What a lovely butterfly!" Nay, it is a flower: though it dances in the air with an insect's fluttering flight, and seems to present in its broad wings of yellow and orange, and in its long and slender members, an insect's form and hues, it is but a flower fixed at the end of a lengthened stalk, which hangs from, a mass of leaves and bulbs, seated in the fork of this huge mahogany-tree.

We will neglect the flower, curious and beautiful as it is, and examine this crowded mass of roots and fleshy leaves and oval bulbs.

Tracing the slender lengthened footstalk to its origin, we see that it springs from the lower part of a flat, ovate, or nearly round, ridged, pseudo-bulb, of a purplish-green hue, of which there are many, much crowded together. The point of issue of the flower-stalk is concealed by an enveloping husky scale, which is the withered condition of a former leaf. From the base of another bulb a thick obtuse cone is pushing forth, which is the commencement of a new leaf-shoot; and here is one considerably advanced. In this latter there is nothing very remarkable; it is a thick, growing shoot, formed by fleshy leaves nearly doubled together, each sheathed by its predecessor. But soon this will cease to grow, and the point will dilate into an oval bulb, which will be a reservoir of nutriment for the future flower. In fact it will add another to the matted mass of bulbs which are already accumulated, crowned with two great thick, leathery, ovate, brown-spotted leaves, and marked with the scars of the leaves which are now growing, but which will then have sloughed away.

In this Oncidium, then, we have evidently a record of many bygone processes. Before the flower could open, the flower-stalk must have been developed; before this, the pseudo-bulb must have been formed; before this, there must have been a well-formed leaf-shoot, which must have been first a conical bud pushing forth from some anterior bulb;--or, if that shoot had been the first of the mass, then it must have looked back to a seed, which of course looked back to the capsule of a pre-existent flower, and so on.

Yet this is all fallacious; for the Butterfly-flower is but just created.

As beautiful, if less curious, is the crowded spike of purple blossom that adorns the tall stalk of this terrestrial Orchis. The flower-stalk springs from the midst of a few large spotted leaves, which terminate below in an irregular fleshy tuber of glutinous consistence. This tuber is shrivelled, and is in process of exhaustion and decay; but a horizontal stem has pushed out underground, which has at its extremity a second tuber, as yet immature, but plump and swelling. This growing tuber contains the elements of the leaves and flower-spike of next season: the shrivelling one was, last year at this period, in exactly the same condition as the swelling one is now; it too was pushed out horizontally from a preceding one which was then shrivelling, and so backward. These pre-existing stages can with certainty be announced by the vegetable physiologist; who yet would be deceived in this instance, because the plant has been but just created.

This elegant Gladiolus that displays its tall spike of crimson blossoms from the midst of its flattened folded leaves, affords us a similar example of retrospective energy. If I dig away the light soil from around its base, I discover two globose corms, fleshy swellings of the stem, accumulations of nutriment obtained during the vegetative activity of the plant, and destined to support it during the season of inaction, and therefore stored up for that purpose.

The uppermost of these globose corms is that of the present season; it is as yet small and immature, being in process of formation by the assimilation, consolidation, and deposition of new matter by the action of the leaves. This is sheathed in the tubular bases of the leaves, which expand above; and it is seated on a larger, riper, and more spherical corm, which is wrapped in a brown fibrous skin. This is the matter which was deposited in the course of last spring and summer, and the brown skin is the remains of the leaves of last year. This corm has remained inactive, since the decay of last year's leaves, until this winter, when the root fibres, which we see descending from the lower surface, began to form, and an upward prolongation of the stem followed, which, as it grew, swelled into the upper corm.

In the centre of the under surface of the corm of last season, in a depression surrounded by the white root-fibres, there are some almost decayed remains of a deep brown hue. These are the last vestiges of the preceding year's corm, and they exhibit the condition in which the large corm will be next spring, when the small half-formed one will be in the state and position of this larger one, and will in like manner be surmounted by its rising successor.

Thus there are in this plant ocular proofs of two years' history before the present; yet these proofs are invalidated by the fact of its creation this day.

Behold now that singular plant, the Grass-tree (Kingia australis), displaying what seems an immense tuft of wiry grass elevated on the summit of a trunk which is formed of the united bases of myriads of decayed leaves, the representatives of many generations of these organs. The silvery leaves which constitute the existing crown, and the numerous spikes of blossom which stand up in a circle diverging from the midst of them, give to this plant a most striking effect. That, however, is not our present concern, but the evidences which we may be able to gather from it of a previous history. For some distance below the living leaves, the trunk is connected by the withered, hanging, but still persistent leaves of several successive developments, a ragged drapery, of which we might certainly say--

"----when unadorn'd, adorn'd the most."

The lower portion of the stem is, however, destitute of the decayed leaves themselves, the lozenge-formed bases of them alone remaining, still separable, indeed, but sufficiently compact to make in the aggregate a sub-cylindrical column of loose texture, which may in familiar parlance be termed a trunk. This portion is marked by alternate enlargements and constrictions of the outline, which appear to indicate seasonal growths.

The specimen before us is about twenty feet in height, exclusive of the crown; supposing these swellings to mark a year's growth, and to be continued in the same proportion on that part of the trunk which is masked by the decayed leaves as on the exposed part, we should conclude this tree to be about thirty-five years old; for there are about thirty-four such swellings, each of which contains about four hundred of the lozenge-shaped bases of the fallen leaves.