Harper's new monthly magazine 7 / 1857
Lichens are a race of tiny plants but little known to the world, and yet possessed of a beauty by no means inferior to that of more gorgeous flowers or loftier trees. Man is but too apt to admire the boundless wealth and beauty of our great mother, Nature, only where gigantic proportions arrest his attention, or when the storm of enraged elements makes him aware of his own insignificance. Surely his head was not set on high that he might despise low things! But to see the beauties with which every corner and crevice is decked, to read the lessons conveyed in Nature's subtlest works, more than the eye is required. We must be willing and able to listen to every beetle's lowly hum, to greet every flower by the wayside as it looks up to us and to heaven, and to question every stone, every pebble. If we this look upon the tiny lichens around us, we will here also soon learn, by the aid of the microscope, that even in the smallest proportions
"not a beauty blows,
And not an opening blossom breathes in vain."
Few only, it is true, are seen by the naked eye as they cover a stone with their warm mantle or "deck the rough castle's rifted tower." No old decaying rock, no crumbling rain, and no ancient forest-chapel is without its forest of tiny lichens and mosses, that have settled down in every cleft and crevice, wherever the rain has left a grain of soil or a shadow of moisture. It is these green or yhellow little plants that give to rock, ruin, and chapel their venerable appearance. They enliven the monotonous coloring of stones, and mark, as it were, the footprints of Time, and the traces of organic life upon the apparently lifeless masses. The stone thus bevomes a very museum of varied productions, and the tiny plants connecting him, immovable and unfeeling as he appears, with their own merry kingdom, thus carry him into the great, joyous circle of living nature.
The strange and inexplicable beauty of simple walls and angular rocks is mainly due to these lichens, who, together with their brethren, the mosses, present an ever fresh and ever declining but never expiring life, and thus fill the heart of man, he knows not how, with sweet hope and tender solace.
They are the most modest children of Nature. Even when they appear in groups and in larger masses, they seem to be, at first sight, but stains and unsightly excrescences. We are, perhaps, most familiar with those that assume a bright orange color on the trunks of old trees, and these are ever seen on that side which is most exposed to warm and moist currents of air, or where a hawthorn "with moss and lichen gray, fies of old age." If we examine these strange, fastidious spots more closely, we find that they consist of a very peculiar growth, which presses closely upon the rough bark. Now it is so interlaced and interwoven with the latter that it can hardly be severed from tree or rock, and then again it clings to it by means of a thousand diminutive year of her rooths, which hold to their resting-place with amazing tenacity. From the roundish, well-edged leaflets, which look as if they were grizzled and wrinkled by premature age, there rise numbers of tiny, delicate plates of similar color. Such is the most common of all the wall-lichens (Parmelia parietina), as seen in Figure 1, which we find in all climes and all zones, though it is said that the humble little plants prefer of all others the bark of Italian poplars. From afar already its bright yellow color discloses the stranger, and shows us at once the higher rank which lichens claim over fungi in the great kingdom of plants. For they possess - the first among the lower orders - the distinguishing mark of true vegetables, the chlorophyle or green color, although as yet but in very minute quantities. Hence also their common use for the purpose of dyeing. Of old, already Scotch minstrels tells us that, "like the Feldelsen of the Saxons", the usual dress of the fairies was green, though on moors they have been sometimes observed in heath-brown or in weeds dyed with stoneraw or lichen, for
"About mill-dams and green brac-faces
Both elrich elfes and brownies stayed,
And green-gown'd fairies danced and played."
Now they serve mainly the poorer classes of Northern Europe to dye their stockings and nightcaps an orange-brown color, or merry children to stain with their bright hues their eggs at Easter. The golden-yellow lichen, which we find on all roofs and on many an ancient tree, serves also as a dye-stuff to the industrious peasant. The Canary Isles send annually more than 3000 cwt. of brilliant ponceau-red Orseille to Europe; it appears afterward as Lacmus in various branches of industry. Sweden sends whole ship-loads of her strange but most useful Lecanora; and the coasts of England, as well as those of the Mediterranean, furnish richly-tinted Roccellæ (Figure 2) and Variolaria, which the painters employ in painting walls blue, while the busy housewife "blues" thus her linen, and the chemist relies upon it as an unfailing test in his science.
Other varieties of the same wall-lichen assume at first a beautiful circular form, resembling, in outline and shape, the fairest rose (Figure 3); and of these it has been said, with qunint but truthful words:
"Careless of thy neighborhood,
Thou dest show thy pleasant face
On the moor and in the wood,
In the lane - there is no place,
Howsoever mean it be,
But 'tis good enought for thee;"
for there are, in reality, but few surfaces long exposed to wind and weather which are not soon protected by the warm cover of these lichens. Our roofs and our fences, the trunk of a tree, and the rock in the moors, the earth-capped dyke, and the sterile sea-bank - in fact, all places but sparingly supplied with moisture, but freely exposed to air and light, are clad in ever-varying colors by these beautiful children of Nature. The far-famed Cathedral of Munster may be truly said to be gilded by these tiny lichens. Nor must we follow the vulgar error, in considering them all as parasites that live on the labor and the very life's-blood of other plants. These serve them merelly as a firm foundation, and their true food they derive from the vatery vapors in the air, from the blessed rain, and frequent dews.
While in some varieties broad leaves cover the surface, and here and there only little deep dishes arise, full of precious though almost invisible seed, others present most tiny and withered leaves, but expand their seed-bearing vessels to larger size and most graceful forms. They abound already in the temperate zone, and furnish large masses of turf; but they increase in number as they approach the inhospitable North, until they finally become the sole representative there of the vegetable kingdom. Bearing on high their elegant goblets, from which they derive their name (Cledonia pyxidata), as in Figure 4, they appear to the naked eye like dwarfish shrubs, or, if we look at them closely, like whitish-gray corals with most diminutive branches. The little cps or goblets are open at the top, and upon the edge there sit, in a circle around, the prettiest little beads of handsome brown or scarlet. Many a fair wreath is woven of these so-called mosses, and sold in the great cities of Europe, and few handsomer ornaments can be found in the fiar kingdom of Flora.
Very different appear, at first sight, the long, venerable gray-beards that hang from the lofty branches of ancient firs and spruces, or from the still more imposing hoary-headed cypresses of our South. Nothing can exceed the picturesque air which they give to the old giants of forest as they now dance wildly in the summer breeze around the grand tree that has withstood there the storms of uncounted ages, and now hang silent and solemn from the branches of the talles of all whom the lightning of heaven has shattered and broken. As the pale light of the moon falls upon their vague, floating outline, weird, woeful fancies enter the mind, and a thousand spectres and spirits are seen hovering under the ghastly garlands. These also are but lichens of larger size; and as their tiny, thread-like stems and branches are too feeble to stand, they hang thus, in apparently listless despair, from their hight, airy home.
A smaller sister, the common Beard Lichen (Usnea barbata), as seen in Figure 5, is found in all forests, especially where evergreens have the majority, and most abundantly in mountainous regions. This, with some other varieties of lichens, constitute the "idle moss" of Shak[e]speare; as in fact, nothing is more commong among our poets than to mingle lichens and mosses without distinction. Thus Southey also says it is
"Not undelightful now to roam
The wild heath sparkling on the sight;
Not undelightful now to pace
The forest's ample rounds;
And see the spangled branches shine,
And mark the moss of many a hue,
That varies the old tree's brown bark,
Or o'er the gray stone spreads."
Stranger still are those children of this much-despised family, that look little better than a mere crust - now thin, like the merest dash of green color, and now reaching a more respectable thickness. They also cover rocks and trees, though rarely the bare earth, and adorn them with their quaint outlines and bright yellow color. One of these simplest of lichens is not unlike a map of German principalities, and hence its name of Geographical Lichen (Lecidea geographica). It is this tiny plant (Figure 6) which Alexander Von Humboldt has made so interesting by discovering it at a height of 18,096 feet, the last child of the vegetable kingdom at that unsurpassed elevation, close to the top of Chimborazo. For as the algæ descend to a depth in the vast ocean of which we can form as yet but a vague and uncertain idea, so the tiny lichens ascend to regions where all other life has long since ceased to exist. Only ten feet below the ever-pure peak of the Jungfrau, and close to the eternal snows of Mont Blanc, there appear still large numbers of small but vigorous lichens. They alone are enabled - we know not yet for what great purpose - to bear the almost incredible rarification of air at such a tremendous height, as the algæ down in the deep sea thrive and prosper under a pressure of 375 atmospheres! And how closely they cling to the hard stone they hold in such loving embrace! As if Nature had varnished over the rough sides of her neglected children, these lichens can not be loosened from their home by the most careful efforts. The kife does not succeed in detaching them, or at least they perish in the attempt, and are seattered about as shapeless powder. The chisel itself must come to our aid, and cut off a chip of the stone to enable us to bring the tiny plant under the microscope.
Unfortunately, however, the substance of which these little plants consist is so dense and solid that even the diminutive walls of their tiny cells seem to defy the power of the microscope. Only extremely thin layers can well be examined, and then they reveal to us the long-unsuspected fact, that their apparently most simple form, whether it be like a shrub or a beard, a mere crust or a many-branched tree, always consists of three distinct layers. THe middle part is ever found to contain large globular cells of greenish color, while the outer and inner layers consist of lengthened cells, which often assume the form of long threads or tiny branches. The tender filaments, of most varied and often very beautiful patterns, penetrate the bark upon which such lichens grow, and soon intereweave with each other in a manner resembling a closely-knit net-work. Their spores, which here also replace the seed-grains of higher plants, grow in long, club-shaped branches, in which they lie closely packed in two rows. These quaint store-houses at last open at the end, and send forth a vast number of diminutive grains, that look for all the world like stains or tiny dots on the ligter surface. Under the microscope, however, they assume truly wondrous shapes, and are seen now as round or semi-circular buttons, and now as flat, shield-shaped discs; at one time they look like tiny cups and saucers with upturned edges, at another like long hollow tubes. Some are said even to resemble Arabic writing with amazing fidelity.
In its first childhood the fruit of lichens is always found in the shape of a well-closed globule, which contains as its kernel a curious contrivance for the production of sporules, the so-called thalamium. With manyh lichens it retains this form until the spores are fully matured, and then it either bursts suddenly asunder, or it permits them to escape through a tiny opening at the end. With other lichens, however, the young fruit opens very soon, and spreads out into the form of a plate or shield, over the upper side of which is stretched the thalamium (Figure 7). Such is the fruit of the common cup-lichen, of which a small part is seen in Figure 8, moderately magnified, while in Figure 9 a single spore is presented eight hundred times larger than in reality, consisting of two distinct cells in their common home, and containing tinydrops of oil in their inner chambers. Very few lichens, however, have as yet been discovered which bear real fruit of this kind. It seems as if they could not mature except under peculiarly favorable circumstances, and their fruits do not even appear but at an extremely old age. The spores, moreover, grow with surprising slowness, and form thus a strange, striking contrast with the same productions in fungi. It is, therefore, but rarely that we can meet with fruit-bearing lichens; and were it not for the wondrous wisdom displayed in all the procinces of this great, though often invisible kingdom, these humble plants would appear but little secured against utter extinction.
But lichens also, like mosses and algæ, have still another method of increasing their numbers. Even the naked eye can see under the carefully-raised upper layer a slight green tissue, which the microscope shows us to consist of a large mass of diminutive globular cells. These have been called Conidia, because they also serve to produce germs when detached from the mother plant. After a while - we know not exactly at what period of their existence - they make their way through the upper layer, and soon change into new individuals, of the same kind as their parents.
Hardy and long-lived as all lichens are, they find in these qualities also a better protection than even the uncounted millions of sporules afford to their humbler brethen, the fungi. Their cells, as we mentioned, are of strong, stour fabric, and possess, moreover, an astounding faculty of reviving after a long and deep slumber. Many love to live upon a soil but little adapted to retain moisture; others, like the Lazzaroni of Naples, will not work even to live. Carelessly and listlessly they lie in the bright sunshine, and implore with Stoic patience, by their miserable appearance, the pity of passing clouds. In these times of want and drought they shrink and shrivel until nothing seems farther from them than life. Pale and rigid, they are the very images of desolation, and crumble under the hand into impalpable dust. Yet no sooner has an early dew or a soft rain - nay, even a faint mist - merely touched their unsightly form, than they begin drinking in moisture with amusing avidity, and, lo and behold! are many minutes passed, they expand and increase, until, as if by the touch of a magic wand, they have recovered their fresh, joyful color and youthful vigor. Thus they would hardly appear the same plants in their days of dryness and after a rain. Even the common lichens that grow in our orchards look ordinarily as if dressed in sad colored livery, because their had, tough skin lies close toth e bark of the trees, and thus assumes the grayish-brown hues of the latter. But as soon as moisture gladdens their little leaves, they swell and soften; they become now transparent, and suffer the pretty green cells in their interior to shine through the outer membrane. Others, again, who live on lofty mountain heights, or on sandy heaths, in the Steppes of the Kirghise, or on the plains of the East, are not seen at all during the dry season. With the first warm rain, however, they rise and swell of a sudden, so that the credulous children of those regions fancy the mysterious plants, which now cover the ground to the height of several inches, have miraculously fallen from the skies. True Proletarians of the vegetable kingdom, they care not for the future, but live only in the enjoyment of the present, and providing not, as most other plants do, for the dyas of want, they must needs spend a large part of their life in silent slumber. All the more they seem to rejoice in their brief time of enjoyment. How they abound and luxuriate in the tropical regions during all winter! Then is their time to thrive and to prosper; and then they display all the wondrous beauty with which even their humbler races were endowed by an all-bountiful Maker. Thus they pass, in ever-changing fate, like man himself, from darkness to light, from rest to activity, and often reach an amazing old age. Some of the crust lichens that grow upon rocks, it is believed, have alternated in this manner, between life and death, during more than a thousand years; and yet they are ever ready still, under a gentle shower, to unfold their graceful leaves, and to blossom anew in brilliant green colors.
Lichens are, moreover, very far from being idle intruders upon the province of others, nor even mere ornaments woven into the bright carpet that covers our earth. Already humbler animals subsist upon these tiny plants. There is, among others, an odd kind of catepillar, who assumes the greenish garb of lichens, and marks it with black spots and stripes, until he so closely resembles the bed on which he rests, that only most careful research can discover the strange intruder. Birds, also, and especially humming birds, know well the art to cover their nests so skillfully all around with tender lichens, that only the practiced eye remains undeceived.
The well-known Reindeer Moss (Cladonia rangiferina, as seen in Figure 10, sustains for months the life of a whole noble race of animals, without whom a large portion of our globe would be but a desert, unfit to be the abode of man. When long, merciless winter has covered all the wide waste regions with his mournful pall, and the blood-red disk of the sun hardly dares to show itself above the horizon, life seems extinct, and death alone to reign there supreme. As far as the eye can reach, nothing is seen but the bare, blank plain, without a tree, a plant, or an herb. Far down in the lowest dens the summer sun has thawed the frozen ground for a few inches, but on the sides and slopes of gentler elevation nothing but ice and snow is apparently found; yet here it is that the heaven-implanted instinct of the sagacious reindeer leads them to dig with powerful hoof and broad-branching antlers, in order to find there, deep under the snow, their long-prepared food. Thus they live, for the larger part of the year, on the sall, simple plants, and eat the tender, whitis-gray leaves with the same relish with which the goat browses on the rich, fragnant grasses of Alpine meadows.
For all lichens are amply endowed with starch; and with this not only most of the cells are filled, but even the walls themselves consist of nutritious starch. Hence the peculiar power of the Iceland Moss (Cetraria Islandica, Figure 11. A greenish-brown, almost unsigtly growth, but sligtly attached to its early home, the low grounds of northern regions, and bearing almost invisible fruit, it is still the great comfort of many a poor sufferer, the help of the ablest physician. Even the common wall lichen above mentioned proved a friend to man in times of need, and when least expected. During the great wars of Napoleon, when the whole Continent was under embargo, and the almost indispensable quinine could not be imported into Germany, chemists and druggists remembered the peculiar chemical nature of these lichens, and drew from them their ample stores of medicinal bitter. Physicians soon adopted it generally, and prescribed it as an admirable substitute for the more costly bark of America. From their wealth in starch comes also the nutritious character of the far-famed swallow-nests of Chinese islands, paid by their weigth in gold, which consist mainly of tiny lichens.
But these humble and little-known plants serve man not merely to tickle a fastidious palate or to soothe his suffering in the hour of sickness; they actually support him in times of need. A leather-like lichen grows largely in the limestone mountains of Northern Asia, and serves in times of famine, at least, as food to the roving Tartars. In the polar regions of Europe similar lichens are carefully soaked and boileddown to free them of their original bitterness, and then cooked with milk or baked into bread. Scanty lichens of this kind, called Tripe de Roche, which had to be dug out from under sheltering loads of snow, were, not for days but for whole months, the sole food of the unfortunate Franklin and his companions.Surely such usefulness ought not to be ungratefully ignored. We are all well aware that thousands of Guarana Indians depend upo nthe Mauritius palm for their food and drink, their clothing and dwelling; that the gentle children of the South Sea Islands are in like manner supported by the cocoa palm; and the Hindoo, who lives on vegetables only, by his banana. The dweller in the desert points proudl to the grateful date-tree as the noblest among plants, and honors it with the most flattering title oft he "Camel of Plants." But how few of us ever think of the humble, microscopic lichen as deserving a place by the side of the nboble palm and the ancient banana among the benefactors of mankind!