85. p. 223—“Palms.”
It is remarkable, that of this majestic form of plants—the Palms—some of which rise to more than twice the height of the Royal Palace at Berlin, and which the Indian, Amarasinha, has very characteristically called “kings among grasses,”—only fifteen species had been described up to the time of the death of Linnæus. The Peruvian travellers, Ruiz and Pavon, added only eight; whilst Bonpland and myself, traversing a greater extent of country, from 12° south lat. to 21° north lat., described twenty new species, and distinguished as many more which we named, without however being able to procure their blossoms in a perfect state.[NV] At present (forty-four years after my return from Mexico) more than 440 species of palms, from both continents, have already been scientifically described, including the East Indian species arranged by Griffith. The “Enumeratio Plantarum” of my friend Kunth, which appeared in 1841, contains no fewer than 356 species.
The very few palms belonging, like our Coniferæ, Quercineæ, and Betulineæ, to social plants, are the Mauritian Palm (Mauritia flexuosa), and the two species of Chamærops, of which the Chamærops humilis covers whole tracts of land at the estuary of the Ebro and in Valencia, while the other, Chamærops Mocini, which we discovered on the Mexican shore of the Pacific, is entirely without prickles. In the same manner as there are some species of palms, including Cocos and Chamærops, which are peculiar to sea-coasts, so also is there a certain group of Alpine palms belonging to the region of the tropics, which, if I mistake not, was wholly unknown before my South American journey. Almost all these species of the palm family grow in plains and in a mean temperature of 81°.5 and 86° Fahr., seldom advancing higher up the sides of the Andes than to 1900 feet. The beautiful wax palm (Ceroxylon andicola), the Palmetto of Azufral at the Pass of Quindiu, (Oreodoxa frigida), and the reed-like Kunthia montana (Caña de la Vibora) of Pasto, all flourish at elevations varying from 6400 to 9600 feet above the level of the sea, where the thermometer frequently sinks in the night to 42°.8 and 45°.5 Fahr., and the mean temperature is scarcely 57° Fahr. These Alpine palms are interspersed with nut-trees, yew-leaved species of Podocarpus, and oaks, (Quercus granatensis). I have determined, by accurate barometric measurements, the upper and lower limits of the wax palm. We began to observe it first on the eastern declivity of the Cordilleras of Quindiu, at an elevation of 7929 feet, from whence it ascended to the Garita del Paramo, and Los Volcancitos, as high as about 9700 feet. The distinguished botanist, Don José Caldas, who was long our companion in the mountains of New Granada, and who fell a victim to Spanish party hatred, found, many years after my departure from the country, three species of palms in the Paramo de Guanacos, in the immediate vicinity of the limit of perpetual snow, and therefore, probably at an elevation of nearly 14,000 feet.[NW] Even beyond the tropical region (in lat. 28°), Chamærops Martiana[NX] rises on the advanced spurs of the Himalaya range to a height of 5000 feet.
When we consider the extreme geographical and, consequently, also the climatic limits of palms at spots which are but little elevated above the level of the sea, we find that some forms (the Date Palm, Chamærops humilis, Ch. palmetto, and Areca sapida of New Zealand,) advance far within the temperate zone of both hemispheres, to districts where the mean annual temperature scarcely reaches from 57° to 60° Fahr. If we form a progressive scale of cultivated plants in accordance with the different degrees of heat they require, and begin with the maximum, we have Cacao, Indigo, Bananas, Coffee, Cotton, Date Palms, Orange and Lemon trees, Olives, Spanish Chesnuts, and Vines. In Europe, Date Palms, together with Chamærops humilis, grow in the parallels of 43½° and 44°, as, for instance, on the Genoese Rivera del Ponente, near Bordighera, between Monaco and San Stefano, where there is a palm grove, numbering more than 4000 trees; also in Dalmatia, near Spalatro. It is remarkable that the Chamærops humilis is of frequent occurrence in the neighbourhood of Nice and in Sardinia, whilst it is not found in the Island of Corsica, lying between the two. In the New Continent, the Chamærops palmetto, which is sometimes more than 40 feet high, does not advance further north than 34°; a circumstance that may be explained by the inflection of the isothermal lines. In the southern hemisphere, Robert Brown[NY] found that palms, of which there are only very few (six or seven) species, advance as far as 34° in New Holland; while Sir Joseph Banks saw an Areca, in New Zealand, as far as 38°. Africa, which, contrary to the ancient and still extensively diffused opinion, is poor in species of palms, exhibits only one palm (Hyphæne coriacea) which advances south of the equator, only as far as Port Natal, in 30° lat. The continent of South America presents almost the same limits. East of the chain of the Andes, in the Pampas of Buenos Ayres, and in the Cis-Plata province, palms extend, according to Auguste de St.-Hilaire,[NZ] as far as 34° and 35°. The Coco de Chile, (our Jubæa spectabilis?), the only species of palm indigenous in Chili, advances on the western side of the chain of the Andes, according to Claude Gay,[OA] to an equal latitude, viz., to the Rio Maule.
I will here subjoin the aphoristic observations which, in March, 1801, I noted down while on board ship, at the moment we were leaving the palm region surrounding the mouth of the Rio Sinu, west of Darien, and were setting sail for Carthagena de Indias.
“In the space of two years, we have seen as many as 27 different species of palms in South America. How many then must have been observed by Commerson, Thunberg, Banks, Solander, the two Forsters, Adanson, and Sonnerat, on their extensive travels! Yet, at the moment I am writing, our vegetable systems recognise scarcely more than from fourteen to eighteen methodically described species of palms. The difficulties of reaching and procuring the blossoms of palms are, in fact, greater than can well be conceived; and, in our own case, we were made peculiarly sensible of this in consequence of our having directed our attention especially to palms, grasses, cyperaceæ, juncaceæ, cryptogamia, and numerous other subjects hitherto much neglected. Most of the palms flower only once a year, and this period near the equator is generally about the months of January and February. How few travellers are likely to be in the region of palms precisely during this season! The period of blossoming of particular trees is often limited to a few days, and the traveller commonly finds, on his arrival in the region of palms, that the blossoms have passed away, and that the trees present only fructified ovaries and no male flowers. In an area of 32,000 square miles, there are often not more than three or four species of palms to be found. Who can possibly, during the brief period of flowering, simultaneously visit the various palm regions near the Missions on the Rio Caroni, in the Morichales at the mouth of the Orinoco, in the valley of Caura and Erevato, on the banks of the Atabapo and the Rio Negro, and on the declivity of the Duida? There is, moreover, great difficulty when the trees grow in thick woods or on swampy shores (as at the Temi and Tuamini), in reaching the blossoms, which are often suspended from stems formidably armed with huge thorns, and rising to a height of between 60 and 70 feet. They who contemplate distant travels from Europe for the purpose of investigating subjects of natural history, picture to themselves visions of efficient shears and curved knives attached to poles, ready for securing anything that comes in their way; and of boys who, obedient to their mandates, are prepared, with a cord attached to their feet, to climb the loftiest trees! Unfortunately, scarcely any of these visions are ever realised; while the flowers are almost unattainable, owing to the great height at which they grow. In the missionary settlements of the river net-work of Guiana, the stranger finds himself amongst Indians, who, rendered rich and independent by their apathy, their poverty, and their barbarism, cannot be induced either by money or presents to deviate three steps from the regular path, supposing one to exist. This stubborn indifference of the natives provokes the European so much the more, from his being continually a witness of the inconceivable agility with which they will climb any height when prompted by their own inclination, as, for instance, in the pursuit of a parrot, an iguana, or a monkey, which, wounded by their arrows, saves itself from falling by its prehensile tail. In the month of January the stems of the Palma Real, our Oreodoxa Regia, were covered with snow-white blossoms, in all the most frequented thoroughfares of the Havannah, and in the immediate vicinity of the city; but, although we offered, for several days running, a couple of piastres for a single spadix of the hermaphrodite blossoms to every negro boy we met in the streets of Regia and Guanavacoa, it was in vain, for, in the tropics, no free man will ever undertake any labour attended by fatigue unless he is compelled to do so by imperative necessity! The botanists and painters of the Royal Spanish Commission of Natural History under Count Don Jaruco y Mopox (Estevez, Boldo, Guio, Echeveria), confessed to us that, for several years, they had been unable to examine these blossoms, owing to the absolute impossibility of obtaining them.
“After this statement of the difficulties attending their acquisition, the fact of our being only able, in the course of two years, systematically to describe twelve species of palms, although we had discovered twenty species, may be understood; but I confess it would hardly have been credible to me before I left Europe. How interesting a work might be written on palms by a traveller, who could exclusively devote himself to the delineation, in their natural size, of the spathe, spadix, inflorescence and fruits!” (Thus I wrote many years before the Brazilian travels of Martius and Spix, and the appearance of the admirable work on Palms by the former.)
“There is much sameness in the form of the leaves, which are either feathery (pinnata), or fan-like (palmo-digitata); the leaf-stalk (petiolus) is either without thorns or is sharply serrated (serrato-spinosus). The leaf-form of Caryota urens and Martinezia caryotifolia, which we saw on the banks of the Orinoco and the Atabapo, and subsequently in the Andes, at the pass of Quindiu, as high as 3200 feet above the level of the sea, is almost as peculiar among palms as is the leaf-form of the Gingko among trees. The habitus and physiognomy of palms are expressive of a grandeur of character which it is difficult to describe in words. The stem (caudex) is simple, and very rarely divided into branches after the manner of the Dracæna, as in Cucifera thebaica (the Doom Palm), and in Hyphæne coriacea. It is sometimes disproportionately thick, as in Corozo del Sinu, our Alfonsia oleifera; of a reed-like feebleness, as in Piritu, (Kunthia montana), and the Mexican Corypha nana; of a somewhat fork-like and protuberant form towards the lower part, as in Cocos; sometimes smooth and sometimes scaly, as in the Palma de Covijaó de Sombrero, in the Llanos; or, lastly, prickly, as in Corozo de Cumana and Macanilla de Caripe, having the thorns very regularly arranged in concentric rings.
“Characteristic differences also manifest themselves in the roots, which, in some cases, project about a foot or a foot and a half from the ground, raising the stem on a scaffolding, as it were, or coiled round it in a padded-like roll. I have seen viverras and even very small monkeys pass under the scaffolding formed by the roots of the Caryota. Occasionally the stem is swollen only in the middle, being smaller above and below, as in the Palma Real of the island of Cuba. The green of the leaves is either dark and shining, as in Mauritia Cocos, or of a silvery white on the under side, as in the slender fan-palm, Corypha Miraguama, which we saw in the harbour of Trinidad de Cuba. Sometimes the middle of the fan-like leaf is adorned with concentric yellow and blue stripes, in the manner of a peacock’s tail, as in the prickly Mauritia, which Bonpland discovered on the Rio Atabapo.
“The direction of the leaves is a no less important characteristic than their form and colour. The leaflets (foliola) are either ranged in a comb-like manner close to one another, with a stiff parenchyma (as in Cocos Phœnix), to which they owe the beautiful reflections of solar light that play over the surface of the leaves, which shine with a brilliant verdure in Cocos, and with a fainter and ashy-coloured hue in the date-palm; or sometimes the foliage assumes a reed-like appearance, having a thinner and more flexible texture, and being curled near the extremity (as in Jagua, Palma Real del Sinu, Palma Real de Cuba, and Piritu del Orinoco). This direction of the leaves, together with the lofty stem, gives to the palms their character of high majesty. It is a characteristic of the physiognomical beauty of the palm that its leaves are directed aspiringly upwards throughout the whole period of its duration, (and not only in the youth of the tree, as is the case with the Date-Palm, which is the only one introduced into Europe.) The more acute the angle made by the leaves with the upper part of the stem (that is, the nearer they approach the perpendicular,) the grander and nobler is the form of the tree. How different is the aspect of the pendent leaves of the Palma de Covija del Orinoco y de los Llanos de Calabozo (Corypha tectorum), from the more horizontal leaves of the Date and Cocoa-nut palms, and the lofty heavenward-pointing branches of the Jagua, the Cucurito, and Pirijao.
“Nature seems to have accumulated all the beauties of form in the Jagua palm, which, intermingled with the Cucurito or Vadgihai, whose stem rises to a height of 80 or even more than 100 feet, crowns the granite rocks at the cataracts of Atures and Maypures, and which we also occasionally saw on the lonely banks of the Cassiquiare. Their smooth and slender stems rise to a height of from 64 to 75 feet, projecting like a colonnade above the dense mass of the surrounding foliage. These aërial summits present a marked and beautiful contrast with the thickly-leaved species of Ceiba, and with the forest of Laurineæ, Calophyllum, and the different species of Amyris which surround them. Their leaves, which seldom exceed seven or eight in number, incline vertically upwards to a height of 16 or 17 feet, and are curled at the extremities in a kind of feathery tuft. The parenchyma of the leaf is of a thin grass-like texture, causing the leaflets to wave with graceful lightness on the gently oscillating leaf-stalk. The floral buds burst forth, in all species of palms, from the stem immediately beneath the leaves; and the mode in which this takers place modifies their physiognomical character. Thus in some, as in Corozo del Sinu, the sheath is perfectly erect, and the fruit rises like a thyrsus, resembling the fruits of the Bromelia. In the greater number, the sheaths, which in some species are smooth, and in others very prickly and rough, incline downwards. In some, again, the male blossoms are of a dazzling white, and it may then be seen shining from a great distance; but in most species of palms they are yellow, closely compressed, and of an almost faded appearance, even when they first burst from the spathe.
“In palms with feathery leaves the leaf-stalks either burst from the dry, rough, ligneous portion of the stem (as in Cocos, Phœnix, Palma Real del Sinu), or there rises in the rough part of the stem a grass-green, smooth, and thinner shaft, like one column above another, from which the leaf-stalk springs, as in Palma Real de la Havana, Oreodoxa regia, which excited the admiration of Columbus. In the fan-palms (foliis palmatis), the leafy crown often rests on a layer of dry leaves, which imparts to the tree a character of melancholy solemnity and grandeur (as in Moriche, Palma de sombrero de la Havana). In some umbrella-palms, the crown consists of a very few scattered leaves, raised on slender stalks (as in Miraguama).
“The form and colour of the fruit also present more variety than is generally supposed to be the case in Europe. Mauritia flexuosa has egg-shaped fruits, whose smooth, brown, and scaly surface gives them the appearance of young pine cones. How great is the difference between the large triangular cocoa-nut, the berry of the date, and the small stone-fruit of the Corozo! But of all the fruits of the palm, none can be compared for beauty with those of the Pirijao (Pihiguao) of San Fernando de Atabapo and of San Balthasar. They are oval, and of a golden colour (one-half being of a purplish red); are mealy, without seed, two or three inches in thickness, and hang in clusters like grapes from the summits of their majestic palm-trunks.” I have already spoken in the earlier part of this work of these beautiful fruits, of which there are seventy or eighty clustered together in one bunch, and which can be prepared in a variety of ways like bananas and potatoes.
The spathe enclosing the blossom bursts suddenly open in some species of palms, with an audible report. Richard Schomburgk has like myself observed this phenomenon[OB] in the flowering of the Oreodoxa oleracea. This first opening of the blossoms of the palm accompanied with noise, reminds us of Pindar’s Dithyrambus on Spring, and of the moment when in the Argive Nemæa, “the first opening shoot of the date-palm announces the coming of balmy spring.”[OC]
Palms, bananas, and arborescent ferns constitute three forms of especial beauty peculiar to every portion of the tropical zone; wherever heat and moisture co-operate, vegetation is most exuberant and vegetable forms present the greatest diversity. Hence South America is the most beautiful portion of the palm world. In Asia the palm form is rare, in consequence perhaps of a considerable part of the Indian continent beneath the equator having been destroyed and covered by the ocean in some earlier revolution of our planet. We know scarcely anything of the African palms between the Bay of Benin and the coast of Ajan; and we are, generally speaking, as already observed, acquainted with only a very small number of African palm-forms.
Palms, next to Coniferæ, and some species of Eucalyptus belonging to the family of the Myrtaceæ, afford examples of the loftiest growth. Stems of the Cabbage-palm (Areca oleracea) have been seen from 160 to 170 feet in height.[OD] The Wax-palm, our Ceroxylon andicola, which we discovered in the Montaña de Quindiu on the side of the Andes, between Ibague and Carthago, attains the enormous height of 180 to 190 feet. I was able to make an accurate measurement of the trunks of some of these trees, which had been felled in the woods. Next to the Wax-palm, the Oreodoxa Sancona, which we found in flower in the valley of Cauca, and which affords a very hard and admirable wood for building, appeared to me to be the highest of all American palms. The fact, that notwithstanding the enormous mass of fruit yielded by some single palms, the number of individuals of each species growing wild is not very considerable, can only be explained by the frequent abortive development of the fruit, and by the voracity of the enemies by whom they are assailed from all classes of animals. In the basin of the Orinoco, however, whole tribes find the means of subsistence for many months together in the fruit of the palm. “In palmetis, Pihiguao consitis, singuli trunci quotannis fere 400 fructus ferunt pomiformes, tritumque est verbum inter Fratres S. Francisci, ad ripas Orinoci et Guainiæ degentes, mire pinguescere Indorum corpora, quoties uberem Palmæ fructum fundant.”[OE]
86. p. 224—“From the earliest infancy of human civilization.”
We find, as far as history and tradition extend, that the Banana has constantly been cultivated in all continents within the tropical zone. The fact of African slaves having, in the course of centuries, brought some varieties of the Banana fruit to America is as certain as that of the cultivation of this vegetable product by the natives of America prior to its discovery by Columbus. The Guaikeri Indians in Cumana assured us that on the coast of Paria, near the Golfo Triste, the Banana will occasionally produce germinating seeds, if the fruit be suffered to ripen on the stem. It is from this cause, that wild Bananas are occasionally found in the recesses of the forests, in consequence of the ripe seeds being scattered abroad by birds. At Bordones also, near Cumana, perfectly formed and matured seeds have been occasionally found in the fruit of the Banana.[OF]
I have already remarked, in another work,[OG] that Onesicritus and other companions of the great Macedonian, make no mention of high arborescent ferns, although they speak of the fan-leaved umbrella palms and of the tender evergreen verdure of the banana-plantations. Among the Sanscrit names given by Amarasinha for the Banana (the Musa of botanists) we find bhanu-phala (sun-fruit), varana-buscha, and moko. Phala signifies fruit generally. Lassen explains Pliny’s words (xii. 6), “Arbori nomen palæ, pomo arienæ,” to this effect, that “The Roman mistook the word pala, fruit, for the name of the tree, whilst varana, changed in the mouth of a Greek to ouarana, was transformed into ariena. The Arabic mauza, our Musa, may have been formed from moko. The Bhanu fruit seems to approach to Banana fruit.”[OH]
87. p. 224—“Form of the Malvaceæ.”
Larger forms of the Mallow appear, as soon as we have crossed the Alps; Lavatera arborea, near Nice and in Dalmatia; and L. olbia, in Liguria. The dimensions of the Baobab (monkey bread-tree) have already been given. (See pp. 270–272.) With the form of the Malvaceæ are associated the botanically allied families of the Byttneriaceæ, (Sterculia, Hermannia, and the blossoms of the large-leaved Theobroma Cacao, whose flowers break forth from the bark of the trunk as well as from the roots); the Bombaceæ (Adansonia, Helicteres, and Cheirostemon); and, lastly, the Tiliaceæ (Sparmannia Africana). Our Cavanillesia plantanifolia of Turbaco, near Carthagena in South America, and the celebrated Ochroma-like Hand-tree, the Macpalxochiquahuitl of the Mexicans, (from Macpalli, the flat of the hand,) Arbol de las manitas of the Spaniards, our Cheirostemon platanoides, are splendid representatives of the mallow form. In the last named, the anthers are connected together in such a manner as to resemble a hand or claw rising from the beautiful purplish-red blossoms. There is in all the Mexican free states only one individual remaining, one single primæval stem of this wonderful genus. It is supposed not to be indigenous, but to have been planted by a king of Toluca, about five hundred years ago. I found that the spot where the Arbol de las Manitas stands is 8825 feet above the level of the sea. Why is there only one tree of the kind? Whence did the kings of Toluca obtain the young tree or the seed? It is equally enigmatical, that Montezuma should not have possessed one of these trees in his botanical gardens of Huaxtepec, Chapoltepec, and Iztapalapan, which were used as late as by Philip the Second’s physician, Hernandez, and of which gardens traces still remain; and it appears no less striking that the Hand-tree should not have found a place among the drawings of subjects connected with natural history, which Nezahual Coyotl, king of Tezcuco, caused to be made, half a century before the arrival of the Spaniards. It is asserted that the Hand-tree grows wild in the forests of Guatimala.[OI] We found two Malvaceæ, Sida Phyllanthos (Cavan.), and Sida Pichinchensis, rising in the equatorial region to the great height of 13,430, and 15,066 feet on the mountain of Antisana and at the volcano of Rucu Pichincha.[OJ] The Saxifraga Boussingaultii rises from 600 to upwards of 700 feet higher, on the declivity of Chimborazo.
88. p. 225—“Form of the Mimosæ.”
The delicate and feathery foliage of the Mimosæ, Acaciæ, Schrankiæ, and Desmanthus, may be regarded as peculiarly characteristic of tropical vegetation; although some representatives of this form may also be found without the tropics. In the Old Continent of the northern hemisphere, and indeed in Asia, I can instance only one low shrub, described by Marshal von Bieberstein as Acacia Stephaniana, but which, according to Kunth’s more recent investigations, is a species of the genus Prosopis. This social plant covers the arid plains of the province of Schirvan on the Kur (Cyrus), near New Schamach, as far as the ancient Araxes. Olivier found it also in the neighbourhood of Bagdad. It is the Acacia foliis bipinnatis mentioned by Buxbaum, and which extends towards the north as far as 42° lat.[OK] In Africa the Acacia gummifera (Willd.), extends to Mogador, and therefore as far as 32° north lat.
In the New Continent, Acacia glandulosa (Michaux), and A. brachyloba (Willd.), adorn the banks of the Mississippi and Tennessee, and the Savannahs of the Illinois. The Schrankia uncinata was found by Michaux to penetrate from Florida northwards to Virginia (therefore as far as 37° north lat.). Gleditschia triacanthos is met with, according to Barton, to the east of the Alleghany mountains, as far as 38° north lat., and west of the same range even to 41° north lat. The extreme northern limit of Gleditschia monosperma is two degrees further southward. Such are the boundaries of the Mimosa form in the northern hemisphere, while in the southern hemisphere, beyond the tropic of Capricorn, simple-leaved Acaciæ are found as far as Van Dieman’s Land; the Acacia cavenia described by Claude Gay being even found in Chili between 30° and 37° south lat.[OL] Chili has no true Mimosa, but three species of Acacia; and even in the north of Chili the Acacia cavenia grows only to a height of 12 or 13 feet, whilst in the south, as it approaches the sea-coast, it scarcely rises a foot above the ground. The most sensitive of the Mimosas which we saw in the northern portion of South America, are (next to the Mimosa pudica,) M. dormiens, M. somnians, and M. somniculosa. The irritability of the African sensitive plant was already noticed by Theophrastus (iv. 3), and by Pliny (xiii. 10); but I find the first description of the South American sensitive plants (Dormideras) in Herrera (Decad. ii. lib. iii. cap. 4). The plant first attracted the attention of the Spaniards, in 1518, in the Savannahs on the isthmus round Nombre de Dios (“parece como cosa sensible”), and it was pretended that the leaves (“de echura de una pluma de pajaros,”) only contracted together when they were touched with the finger, and not when brought in contact with a piece of wood. In the small swamps which surround the town of Mompox on the Magdalena River, we discovered a very beautiful aquatic Mimosa (Desmanthus lacustris), a representation of which is given in our “Plantes équinoxiales” (t. i. p. 55, pl. 16). In the chain of the Andes of Caxamarca we found two Alpine Mimosas (Mimosa montana and Acacia revoluta) growing at elevations of from 9000 to nearly 9600 feet above the level of the sea.
As yet no true Mimosa, (in the meaning of the word as established by Willdenow,) nor even any Inga, has been found in the temperate zone. Amongst all the Acacias the Oriental Acacia Julibrissin, which Forskäl has confounded with Mimosa arborea, endures the greatest degree of cold. In the Botanical Garden of Padua there is a high stem of considerable thickness growing in the open air, although the mean temperature of Padua is below 56° Fahrenheit.
89. p. 225.—“Heaths.”
We do not, in these physiognomical considerations, by any means comprehend, under the name of Heaths, the whole natural family of the Ericaceæ, which, on account of the similarity and analogy in the flowering parts of the plant, include Rhododendrum, Befaria, Gaultheria, and Escallonia; we limit ourselves to the very accordant and characteristic form of the species of Erica, including Calluna (Erica vulgaris, L.).
“Whilst in Europe Erica carnea, E. tetralix, E. cinerea, and Calluna vulgaris, cover large tracts of country, extending from the plains of Germany, and from France and England, to the extremity of Norway; Southern Africa presents the most varied assortment of species. One single species, Erica umbellata, which is indigenous in the southern hemisphere, at the Cape of Good Hope, is again found in Northern Africa, Spain, and Portugal. Erica vagans and E. arborea also belong to the opposite coasts of the Mediterranean. The former is met with in Northern Africa, in the neighbourhood of Marseilles, in Sicily and Dalmatia, and even in England; the second in Spain, Istria, Italy, and the Canaries.”[OM] The common heath, Calluna vulgaris (Salisbury), which is a social plant, covers large tracts from the mouth of the Scheldt to the western declivity of the Ural. Beyond the Ural both Oaks and Heaths disappear. Both are wanting in the whole of Northern Asia, and in all Siberia, as far as the Pacific. Gmelin[ON] and Pallas[OO] have expressed their astonishment at this disappearance of Calluna vulgaris; which, on the eastern declivity of the Ural chain is even more decided and more sudden than one might be led to conclude, from the words of the last-named great naturalist. Pallas merely says, “ultra Uralense jugum sensim deficit, vix in Isetensibus campis rarissime apparet, et ulteriori Sibiriæ plane deest.” Chamisso, Adolph Erman, and Heinrich Kittlitz collected Andromedas but no Calluna in Kamtschatka and on the north-west coast of America. The accurate knowledge which we at present possess of the mean temperature of different portions of Northern Asia, as well as of the distribution of annual heat throughout the different seasons, in no way explains the non-advance of the Heath to the east of the Ural. Dr. Joseph Hooker has treated with much ingenuity, in a note to his “Flora Antarctica,” of the two contrasting phenomena of the distribution of plants, “uniformity of surface accompanied by a similarity of vegetation”, and again, “instances of a sudden change in the vegetation, unaccompanied with any diversity of geological and other feature.”[OP] Is there an Erica in Central Asia? That which Saunders, in Turner’s “Travels to Thibet,”[OQ] has described in the highlands of Nepaul, besides other European plants (Vaccinium Myrtillus, and V. oxycoccus), as Erica vulgaris, is, according to the opinion communicated to me by Robert Brown, probably the Andromeda fastigiata of Wallich. The absence of Calluna vulgaris and of all species of Erica, throughout the whole of the continental part of America is an equally striking fact, since Calluna is met with in the Azores and in Iceland. It has not hitherto been found in Greenland, but it was discovered some years ago in Newfoundland. The natural family of the Ericaceæ is also almost entirely wanting in Australia, where its place is supplied by the Epacrideæ. Linnæus described only 102 species of the genus Erica, but, according to Klotzsch’s observations, this genus comprises 440 true species, after the varieties have been carefully excluded.
90. p. 226—“The Cactus form.”
When the natural family of the Opuntiaceæ is separated from the Grossulariaceæ (species Ribes), and is confined within the limits indicated by Kunth,[OR] we may regard the whole as exclusively American. I am not ignorant, that Roxburgh, in the Flora indica (inedita), mentions two species of Cactus which he regards as peculiar to the south-east of Asia, viz., Cactus indicus, and C. chinensis. Both are widely diffused, originally wild or having become so, and different from Cactus opuntia and C. Coccinellifer; but it is remarkable that this Indian plant should have no ancient Sanscrit name. The so-called Chinese Cactus has been introduced by cultivation into the island of St. Helena. Modern investigations, prosecuted at a period when a more general interest has been awakened in relation to the original distribution of plants, will unquestionably remove the doubts that have frequently been advanced against the existence of Asiatic Opuntiaceæ. We see, in a similar manner, certain vital forms appear separately in the animal world. How long did the Tapir continue to be regarded as a characteristic form of the New Continent! And yet the American Tapir is, as it were, repeated in that of Malacca (Tapirus indicus, Cuv.).
Although the Cactus form belongs, properly speaking, to the tropical regions, there are some species in the New Continent, that are indigenous to the temperate zone on the Missouri and in Louisiana; as, for instance, Cactus missuriensis and C. vivipara. Back, in his northern expedition, saw with astonishment, the banks of the Rainy Lake in lat. 48° 40′ (long. 92° 53′) entirely covered with C. Opuntia. South of the equator the Cactus does not advance further than Rio Itata (lat. 36°) and Rio Biobio (lat. 37¼°) In the part of the chain of the Andes lying within the tropics, I have found species of Cactus (C. sepium, C. chlorocarpus, C. bonplandii) on elevated plains from 9000 to upwards of 10,600 feet above the level of the sea; but in Chili, in the temperate zone, a far more strongly marked Alpine character is exhibited by Opuntia Ovallei, whose upper and lower limits have been accurately determined through barometric measurements by the learned botanist, Claude Gay. The yellow-flowering Opuntia Ovallei, which has a creeping stem, does not descend below 6746 feet, advancing as high as the line of perpetual snow; and even above it, wherever a few masses of rock remain uncovered. These little plants have been gathered at spots lying at an elevation of 13,663 feet above the level of the sea.[OS] Some species of Echinocactus are also true alpine plants in Chili. A counterpart to the much admired fine-haired Cactus senilis is presented by the thick-wooled Cereus lanatus, called by the natives Piscol, which has a fine red fruit. We found it near Guancabamba, in Peru, on our journey to the Amazon river. The dimensions of the Cactaceæ (a group on which the Prince of Salm-Dyck was the first to throw considerable light) present the most striking contrasts. Echinocactus Wislizeni, which has a circumference of seven feet and a half, with a height of four feet and a quarter, is only third in size, being surpassed by E. ingens, (Zucc.) and E. platyceras. (Lem.)[OT] The Echinocactus Stainesii attains a diameter of from two feet to two and a-half; E. visnago, belonging to Mexico, has a diameter of upwards of three feet, with a height of more than four feet, and weighs as much as from 700 to 2000 lbs.; while the Cactus nanus, which we collected near Sondorillo, in the province of Jaen, is so small and so loosely rooted in the sand, that it gets between the toes of dogs. The Melocactuses, which are full of juice even in the driest season, as the Ravenala of Madagascar (wood-leaf in the language of the country from rave, raven, a leaf, and ala, the Javanese halas, a wood), are vegetable springs, which the wild horses and mules open by stamping with their hoofs—a process in which they frequently injure themselves.[OU] Cactus Opuntia has spread during the last quarter of a century in a remarkable manner through Northern Africa, Syria, Greece, and the whole of Southern Europe; penetrating from the coasts of Africa far into the interior, where it associates with the native plants.
After being accustomed to see Cactuses only in our hothouses, we were astonished at the density of the woody fibres in old cactus stems. The Indians are aware that cactus wood is indestructible, and admirably adapted for oars and the thresholds of doors. There is hardly any physiognomical character of exotic vegetation that produces a more singular and ineffaceable impression on the mind of the traveller, than an arid plain densely covered with columnar or candelabra-like stems of cactuses, similar to those near Cumana, New Barcelona, Coro, and in the province of Jaen de Bracamoros.
91. p. 226—“Orchideæ.”
The almost animal-like form occasionally observed in blossoms of the Orchideæ is most strongly marked in Anguloa grandiflora, celebrated in South America as the Torito; in the Mosquito (our Restrepia antennifera); in the Flor del Espiritu Santo (likewise an Anguloa, according to Floræ Peruvianæ Prodrom. p. 118, tab. 26); in the ant-like flower of Chiloglottis cornuta;[OV] in the Mexican Bletia speciosa; and in the whole host of our remarkable European species of Ophrys: O. muscifera, O. apifera, O. aranifera, O. arachnites, &c. The taste for these splendidly flowering plants has so much increased, that the number of species cultivated by Messrs. Loddige, which, in 1813, was only 115, was upwards of 1650 in 1843, and in 1848, the number was estimated at no fewer than 2360. What a treasure of sumptuously flowering and unknown Orchideæ may be inclosed in the interior of Africa wherever there is an abundant supply of water! Lindley, in his beautiful work, On the Genera and Species of Orchideous Plants, 1840, counted exactly 1980 species; whilst Klotzsch at the close of the year 1848 counted 3545.
Whilst the temperate and cold zone possess only terrestrial Orchideæ, growing close to the ground, both forms, the terrestrial, as well as the parasitical, growing on the trunks of trees, are indigenous in the beautiful regions of the tropics. To the former class belong the tropical genera Neottia, Cranichis, and most Habenarias. But we have found both these forms as alpine plants on the declivity of the Andes of New Granada and Quito, viz., the parasitical (Epidendreæ) Masdevallia uniflora (at an elevation of 10,231 feet), Cyrtochilum flexuosum (at 10,103 feet), and Dendrobium aggregatum (at 9485 feet); and the terrestrial forms of Altensteinia paleacea, near Lloa Chiquito, at the foot of the volcano of Pichincha. Claude Gay is of opinion that the Orchideæ supposed to have been found growing on trees in the Island of Juan Fernandez and even at Chiloe, were probably only parasitical Pourretiæ, which advance as far south at least as 40°. In New Zealand, the tropical form of Orchideæ, hanging from trees, is still to be seen as far south as 45°. But the Orchideæ of Auckland and Campbell Islands (Chiloglottis, Thelymitra, and Acianthus), grow on level ground in moss. In the animal world there is at least one tropical form that penetrates further south. The Island of Macquarie (lat. 54° 39′) has an indigenous parrot, which lives therefore in a region nearer to the south pole than Danzig is to the north pole.[OW]
92. p. 226—“Form of the Casuarinæ.”
Acacias, in which the place of the leaves is supplied by phyllodia, Myrtaceæ (Eucalyptus, Metrosideros, Melaleuca, Leptospermum), and Casuarinæ, constitute the sole characteristics of the vegetable world of Australia (New Holland) and Tasmania (Van Diemen’s Land). Casuarinæ with their leafless, thin, thread-like, articulated branches, and their joints furnished with membranous, toothed spathes, have been compared by travellers,[OX] according to differences of species, either with arborescent Equisetaceæ (Horsetails) or with our Scotch firs. I have been much struck with the singular appearance of leaflessness presented by the small thickets of Colletia and Ephedra in South America, near the coast of Peru. Casuarina quadrivalvis penetrates, according to Labillardière, as far south as 43° in Tasmania. The mournful form of the Casuarina is not unknown in the East Indies and even on the eastern coast of Africa.
93. p. 227—“Acicular-leaved trees.”
The family of the Coniferæ (including the genera of Dammara, Ephedra, and Gnetum of Java and New Guinea, which are essentially allied to it, though distinctly separated by the form of the leaf and the whole conformation), plays so important a part in consequence of the number of individuals in each species, and by its geographical diffusion, while it covers in the northern temperate zone, as a social plant, such extensive districts, that we are almost compelled to wonder at the inconsiderable number of the species. We are not acquainted with so many Coniferæ by three-fourths as there are Palms already described, nay, the Coniferæ are numerically less than the Aroideæ. Zuccarini, in his “Contributions to the Morphology of the Coniferæ,”[OY] enumerates 216 species, of which 165 belong to the Northern and 51 to the Southern hemisphere. These proportional numbers must now, in consequence of my researches, be differently expressed, since, with the species of Pinus, Cupressus, Ephedra, and Podocarpus, which Bonpland and I discovered in the tropical part of Peru, Quito, New Granada, and Mexico, the number of the cone-bearing trees flourishing between the tropics amounts to 42. The excellent and latest work of Endlicher[OZ] contains 312 species of Coniferæ now living, and 178 of a primeval mundane period which are now buried in the coal formation, in variegated sandstone, in keuper, and in Jura limestone. The vegetation of the eocene world presents especially to us forms which, by their coëval relationship with several families of the present world, remind us that with it many intervening members have disappeared. The Coniferæ, so frequent in the primeval world, accompany, in particular, the ligneous remains of Palms and Cycadeæ; but in the most recent beds of lignite or brown coal we again find Coniferæ, our Pines and Firs, associated with Cupuliferæ (or Mastworts), Maples and Poplars.[PA]
If the surface of the earth did not rise to great altitudes within the tropics, the strikingly characteristic form of acicular-leaved trees would have remained wholly unknown to the inhabitants of that zone. I took great pains, in common with Bonpland, to trace out, in the Mexican Highlands, the lower and upper boundary line of the Coniferæ and Oaks. The heights, at which both begin to grow (los Pinales y Encinales, Pineta et Querceta), are hailed with joy by those who come from the sea coast, because they announce a climate not yet invaded, as far as experience has hitherto shown, by that mortal disease called the black vomit (vomito prieto, a form of the yellow fever). For the oaks, especially the Quercus Xalapensis (one of the twenty-two Mexican species of oak which we first described), the lower line of vegetation, on the way from Vera Cruz to the capital of Mexico, somewhat below the Venta del Encero, is 3048 feet above the sea. At the western slope of the plateau, between the South Sea and Mexico, the inferior line for oaks is something lower; it begins near a hut named Venta de la Moxonera, between Acapulco and Chilpanzingo, at the absolute height of 2481 feet. I found a similar difference in the lower boundary line of the pine-forest. This boundary, towards the South Sea, in the Alto de los Caxones, north of Quaxinquilapa, is for the Pinus Montezumæ (Lamb.), which we at first had considered to be the Pinus occidentalis (Swartz), at the height of 4092 feet; but towards Vera Cruz, at the Cuesta del Soldado, it rises to 5979 feet. Both these kinds of tree, therefore, the oaks and firs as specified above, descended lower towards the Pacific than towards the Caribbean Gulf. During my ascent of the Cofre di Perote, I found the superior boundary Line of the oaks to be 10,353 feet; that of the Pinus Montezumæ 12,936 feet (about 2000 feet higher than the summit of Mount Ætna) and here, in February, considerable masses of snow had already fallen.
The greater the heights at which the Mexican cone-bearing trees begin to show themselves, the more singular is it, in the island of Cuba (where, at the border of the tropical zone the air, it is true, is cooled down during northerly winds to 46°.6 Fahr.), to see another kind of fir (P. Occidentalis, Swartz), in the plain itself, or on the gentle hills of the Isle of Pines, growing among palms and mahogany trees (Swietenia). Columbus even makes mention of a fir-wood (Pinal) in the journal of his first voyage (Diario del 25 de Nov., 1492), at Caya de Moya, north-east of Cuba. At Haiti, too (St. Domingo), the Pinus occidentalis near Cape Samana descends from the mountains down to the very beach. The stems of these firs, wafted by the gulf-stream to the two Azores, Graciosa and Fayal, were among the principal signs that proclaimed to the great discoverer the existence of unknown lands in the West.[PB] Is it positively ascertained that the Pinus occidentalis is entirely absent from Jamaica, notwithstanding its lofty mountains? We may be permitted to inquire also, what kind of Pinus grows on the eastern coast of Guatimala, since the P. tenuifolia (Benth.) is assuredly found only on the mountains near Chinanta.
On taking a general view of the species of plants which form the upper tree-boundary in the northern hemisphere from the frigid zone to the equator; I find, for Lapland, according to Wahlenberg, in the Sulitelma Mountains (lat. 68°), not acicular-leaved trees but birches (Betula alba), far above the upper limit of the Pinus sylvestris; and for the temperate zone I find in the Alps (lat. 45° 45′) Pinus picea (Du Roi), advanced beyond the birches. In the Pyrenees (lat. 42° 30′), we find Pinus uncinata (Ram.) and P. sylvestris, var. rubra; within the tropics in Mexico (lat. 19°–20°), Pinus Montezumæ extends far beyond Alnus toluccensis, Quercus spicata, and Q. crassipes; and in the snow-crowned mountains of Quito, beneath the equator, Escallonia myrtilloides, Aralia avicennifolia, and Drymis Winteri attain the highest limits. This last species of tree, identical with the Drymis granatensis (Mut.), and the Wintera aromatica of Murray, presents, as Dr. Joseph Hooker has shown,[PC] the most singular instance of the uninterrupted dissemination of the same species of tree from the southernmost part of Tierra del Fuego and Hermit Island, where it was discovered as early as 1577 by Drake’s expedition, up to the northern Highlands of Mexico, over a meridian extent of 86° of latitude or 5160 miles. Where the acicular or needle-leaved trees, as in the Swiss Alps and the Pyrenees, and not the birch as in the extreme north, form the boundary of arborescent vegetation on the loftiest mountains, which they picturesquely encircle, they are immediately followed in their ascent towards the snow-crowned summits, in Europe and Western Asia by the Alpine roses, Rhododendra, and at the Silla de Caracas, and the Peruvian Paramo de Saraguru, by the purplish-red blossoms of the graceful Befariæ. In Lapland the Rhododendron laponicum immediately follows the Coniferous trees; in the Swiss Alps, the Rhododendron ferrugineum and R. hirsutum, and in the Pyrenees the R. ferrugineum alone; and in the Caucasus the R. caucasicum. But R. caucasicum has also been found isolated by De Candolle in the Jura mountains (in the Creux de Vent), 5968 feet lower down, at the inconsiderable height of from 3303 to 3730 feet. If we would trace out the last zone of vegetation near the snow line we must name, according to our personal observation, in tropical Mexico, Cnicus nivalis and Chelone gentianoides; in the cold mountainous tracts of New Granada, the woolly Espeletia grandiflora, E. corymbosa, and E. argentea; in the Andes chain of Quito, Culcitium rufescens, C. ledifolium, and C. nivale;—yellow-blossomed Compositæ, which replace the somewhat more northerly lanose herbs of New Granada, and the Epeletiæ, with which they have so much physiognomical resemblance. This substitution or repetition of similar and almost identical forms in regions that are separated from each other by seas or wide intervening tracts, is a wonderful law of nature. It prevails even in the rarest forms of the floras. In Robert Brown’s family of the Rafflesiæ, separated from the Cytineæ, the two Hydnoræ in Southern Africa (H. Africana and H. Triceps), described by Thunberg and Drege, have, in South America, their counterpart in the H. Americana of Hooker.
Far above the regions of Alpine herbs, of the grasses and the lichens, nay, beyond the boundary of perpetual snow, there occasionally appears a phanerogamic plant, growing sporadically, and as it were isolated, to the astonishment of botanists; and this occurs both within the tropics and in the temperate zone, on fragments of rock which remain free from snow and are probably warmed by open fissures. I have already mentioned the Saxifraga Boussingaulti, which is found at a height of 15,773 feet on the Chimborazo; in the Swiss Alps the Silene acaulis, a clovewort or caryophyllea, has been seen at a height of 11,382 feet. The former vegetates at 640, the latter at 2621 feet above the respective local limits of snow, heights which were determined when both the plants were discovered.
In our European Coniferous woods the Red Pine (or Norway Spruce), and the White (or Silver) Pine show great and remarkable variations as regards their geographical dispersion on the slopes of mountains. Whilst in the Swiss Alps the Red Pine (Pinus picea, Du Roi, foliis compressotetragonis; unfortunately named by Linnæus and by most botanists of our time the Pinus abies!), forms the limit of tree vegetation at the mean height of 5883 feet, and only here and there does the lowly alder (Alnus viridis, Dec., Betula viridis, Vill.), advance higher towards the snow-limit; the White Pine (Pinus abies, Du Roi, Pinus picea, Linn., foliis planis, pectinato-distichis, emarginatis), has its limit, according to Wahlenberg, about 1000 feet lower. The Red Pine does not grow at all in Southern Europe, in Spain, the Apennines, and Greece; and, as Ramond remarks, it is only seen on the slope of the northern Pyrenees at great heights, and is entirely wanting in the Caucasus. The Red Pine extends further to the north in Scandinavia than the White, which latter tree appears in Greece (on the Parnassus, the Taygetus, and the Œta), as a variety with long acicular leaves, foliis apice integris, breviter mucronatis, the Abies Apollinis of the acute observer Link.[PD]
On the Himalaya the acicular-leaved form of trees is distinguished by the mighty thickness and height of the stem as well as by the length of the leaf. The chief ornament of the mountain range is the Cedar Deodwara (Pinus deodara, Roxb.), which word is, in Sanscrit, dêwa-dâru, i.e. timber for the gods, its stem being nearly from 13 to 14 feet in diameter. It ascends in Nepaul to more than 11,700 feet above the level of the sea. More than 2000 years ago the Deodwara cedar near the River Behut, that is, the Hydaspes, furnished the timber for the fleet of Nearchus. In the valley of Dudegaon, north of the copper mines of Dhunpoor in Nepaul, Dr. Hoffmeister, so early lost to science, found in a forest the Pinus longifolia (Royle), or the Tschelu Fir, mixed with the lofty stems of a palm—Chamærops martiana (Wallich).[PE] Such an interspersion of the pineta and palmeta had already, in the new continent, excited the astonishment of the companions of Columbus, as a friend and contemporary of the admiral’s, Petrus Martyr Anghiera, relates.[PF] I myself saw, for the first time, this blending of pines with palms on the road from Acapulco to Chilpanzingo. The Himalaya, like the Mexican highlands, besides its genera of pine and cedar, possesses also forms of the Cypress (Cupressus torulosa, Don.); of the Yew (Taxus Wallichiana, Zuccar.); of the Podocarpus (Podocarpus nereifolia, Brown); and the Juniper (Juniperus squamata, Don., and J. excelsa, Bieberst.; the latter species occurring also at Schipke in Thibet, in Asia Minor, Syria, and the Grecian Islands; on the other hand, Thuja, Taxodium, Larix, and Araucaria, are forms of the New Continent, which are wanting in the Himalaya.
Besides the twenty species of pine with which we are acquainted in Mexico, the United States of North America, in their present extension to the Pacific, present forty-five described species, whilst all Europe can only enumerate fifteen. The same difference between abundance and paucity of forms is shown in the oaks, in favour of the New Continent (a quarter of the world the most connected and most elongated in a meridional direction). It has, however, been very recently demonstrated by the extremely accurate researches of Siebold and Zuccarini to be an erroneous assertion, that many European species of pine, in consequence of their wide distribution throughout Northern Asia, passed over to the Japanese islands, and there mingled with a genuine Mexican species, the Weymouth pine (Pinus strobus, L.), as Thunberg asserts. What Thunberg considered to be European species of pine, are species entirely different. Thunberg’s Red Pine (Pinus abies, Linn.) is P. polita, Sieb., and often planted near Buddhist temples; his northern common fir (Pinus sylvestris) is P. Massoniana, Lamb.; his P. cembra, the German and Siberian stone pine-tree, is P. parviflora, Sieb.; his common larch (P. larix) is the P. leptolepis, Sieb.; his Taxus baccata, the fruit of which the Japanese courtiers eat as a precautionary measure when attending long ceremonies,[PG] forms a special genus and is Cephalotaxus drupacea, Sieb. The Japanese islands, despite the proximity of the Asiatic Continent, have a very different character of vegetation. Thunberg’s Japanese Weymouth pine, which would present an important phenomenon, is moreover a naturalized tree, that differs entirely from the indigenous pines of the New World. It is Pinus korajensis, Sieb., which has migrated from the peninsula of Corea and Kamtschatka to Nipon.
Of the 114 species now known of the genus Pinus, there is not one in the whole southern hemisphere, for the Pinus Merkusii, described by Junghuhn and De Vriese, still belongs to that part of the island of Sumatra which is north of the equator, that is, to the district of the Battas. The P. insularis, Endl., belongs to the Philippines, although at first it was introduced into Loudon’s Arboretum as P. timoriensis. From our present increasing knowledge of the geography of plants, we know that there are excluded also from the southern hemisphere, in addition to the genus Pinus, all the races of Cupressus, Salisburia (Ginkgo), Cunninghamia (Pinus lanceolata, Lamb.), Thuja, one species of which (Th. gigantea, Nutt.) at the Columbia river rises as high as 180 feet, Juniperus, and Taxodium (Mirbel’s Schubertia). I can introduce this last genus here with the greater certainty, inasmuch as a Cape plant, Sprengel’s Schubertia capensis, is no Taxodium, but forms a special genus, Widringtonia, Endl., in quite another division of the Coniferæ.
This absence from the southern hemisphere of the true Abietineæ, of the Juniperineæ, Cupressineæ, and all the Taxodineæ, as likewise of the Torreya, of the Salisburia adiantifolia, and of the Cephalotaxus among the Taxineæ, vividly reminds us of the enigmatical and still obscure conditions which determined the original distribution of vegetable forms. This distribution can by no means be satisfactorily explained either by the similarity or diversity of the soil, by thermal relations, or by meteorological conditions. I have long since directed attention to the fact, that the southern hemisphere possesses, for instance, many plants of the natural family of the Rosaceæ, but not a single species of the genus Rosa itself. Claude Gay informs us, that the Rosa Chilensis, described by Meyen, is a variety that has become wild of the Rosa centifolia, Linn., which has been naturalized in Europe for thousands of years. Such wild-growing varieties occupy large tracts in Chili near Valdivia and Osorno.[PH]
In the whole tropical region of the northern hemisphere we only found one single indigenous rose, our Rosa Montezumæ, and this was on the Mexican highland, near Moran, at a height of 9336 feet. We may count among the strange phenomena observed in the distribution of plants, the total absence of the Agave from Chili, though it possesses Palms, Pourretias, and many species of Cactus; and although A. americana flourishes luxuriantly in Roussillon, at Nice, at Botzen, and in Istria, where it was probably introduced from the New Continent since the sixteenth century, and where it forms one connected line of vegetation from the north of Mexico, across the isthmus of Panama, as far as Southern Peru. With respect to the Calceolarias, I long believed that, like the roses, they were only to be found exclusively on the northern side of the equator. In fact, among the twenty-two species that we brought with us, not one was gathered to the north of Quito and the volcano of Pichincha; but my friend Professor Kunth remarks that Calceolaria perfoliata, which Boussingault and Capt. Hall found near Quito, advances also as far as New Granada, and that this species, as well as C. integrifolia, was sent by Mutis from Santa Fé de Bogotá to the great Linnæus.
The species of Pinus, which are so abundant in the wholly inter-tropical Antilles, as well as in the tropical mountain regions of Mexico, do not cross the isthmus of Panama, and are wholly wanting in the equally mountainous parts of tropical South America, that lie north of the equator; they are equally unknown on the elevated plains of New Granada, Pasto, and Quito. I have advanced in the plains and on the mountains from the Rio Sinu, near the isthmus of Panama, as far as 12° south lat.; and in this territorial extent, of nearly 1600 miles in length, the only forms of needle-leaved trees that I saw, were the taxoid Podocarpus (P. taxifolia), 64 feet high, in the Andes pass of Quindiu and in the Paramo de Saraguru, in 4° 26′ north and 3° 40′ south latitude, and an Ephedra (E. americana) near Guallabamba, north of Quito.
Among the group of the Coniferæ, the following are common to the northern and southern hemispheres: Taxus, Gnetum, Ephedra, and Podocarpus. Long before l’Heritier, the last genus had been very properly distinguished from Pinus by Columbus on the 25th of November, 1492. He says, “Pinales en la Serrania de Haiti que no llevan piñas, pero frutos que parecen azeytunos del Axarafe de Sevilla.”[PI] Species of yew extend from the Cape of Good Hope to 61° north lat. in Scandinavia, consequently through more than 95 degrees of latitude. Podocarpus and Ephedra are almost as widely distributed; and even from among the Cupuliferæ, the species of the oak genus, usually termed by us a northern form, though they do not cross the equator in South America, reappear in the southern hemisphere, at Java, in the Indian archipelago. To this latter hemisphere ten genera of the cone-bearing trees exclusively appertain, of which we will here cite only the most important: Araucaria, Dammara (Agathis, Sal.), Frenela (comprising about 18 Australian species), Dacrydium and Lybocedrus, whose habitat is both in New Zealand and the Straits of Magellan. New Zealand possesses one species of the genus Dammara (D. australis), but no Araucaria. The contrary, by a singular contrast, is the case in New Holland.
In the form of acicular-leaved trees, Nature presents us with the greatest length of stem existing in arborescent productions. I use the term arborescent, for, as we have already remarked, among the Laminariæ (the oceanic algæ) Macrocystis pyrifera, between the coast of California and 68° south lat., often attains a length of more than 400 feet. If we exclude the six Araucarias of Brazil, Chili, New Holland, the Norfolk Islands and New Caledonia, then those Coniferæ are the highest, whose habitat is the temperate zone of the North. As we have found among the family of the palms the most gigantic of all, the Ceroxylon andicola, about 192 feet high, in the temperate Alpine climate of the Andes, so in like manner do the loftiest cone-bearing trees belong, in the northern hemisphere, to the temperate north-western coast of America and to the Rocky Mountains (lat. from 40° to 52°), in the southern hemisphere to New Zealand, Tasmania or Van Dieman’s Land, to Southern Chili and Patagonia, (where the lat. is again from 43° to 50°). The most gigantic forms among the genus Pinus are Sequoia (Endl.), Araucaria, and Dacrydium. I only name those species whose height not merely reaches but often exceeds 200 feet. That the reader may have a standard of comparison, he is reminded that in Europe the loftiest Red and White Pines, especially the latter, reach a height of from 160 to 170 feet; for instance, in Silesia, the pine in the Lampersdorf forest, near Frankenstein, long famous for its altitude, is only 158 feet high, although 17 feet in girth.[PJ]
We give the following examples:—
Pinus Grandis (Dougl.), in New California, attains a height of 202–224 feet.
Pinus Frémontiana (Endl.), also there, and probably of the same height.[PK]
Dacrydium Cupressinum (Solander), in New Zealand, above 213 feet.
Pinus Lambertiana (Dougl.), in North-western America, 223–234 feet.
Araucaria Excelsa (R. Brown), the Cupressus columnaris of Forster, in Norfolk Island and the surrounding rocks, 182–223 feet. The six Araucariæ hitherto known fall into two groups, according to Endlicher:
α. The American (Brazil and Chili), A. brasiliensis [Rich.], between 15° and 25° south lat., and A. imbricata [Pavon], between 35° and 50° south lat.; the latter 234–260 feet;
β. The Australian (A. Bidwilli [Hook.] and A. Cunninghami [Ait.] on the eastern side of New Holland, A. excelsa of Norfolk Island, and A. Cookii [R. Brown] of New Caledonia). Corda, Presl, Göppert, and Endlicher have already found five fossil Araucariæ in lias, in chalk, and in lignite.[PL]
Pinus Douglasii (Sab.) in the valleys of the Rocky Mountains and at the Columbia River (north lat. 43°–52°). That meritorious Scotch botanist, whose name this tree bears, suffered a dreadful death in 1833, when he came from New California to collect plants on the Sandwich Islands. He inadvertently fell into a pit, into which one of the wild bulls of that country, always viciously disposed, had previously fallen. This traveller has described from accurate measurements a stem of P. Douglasii, which at three feet from the ground was 57½ feet round, and 245 feet high.[PM]
Pinus Trigona (Rafinesque), on the western slope of the Rocky Mountains.[PN] This “gigantic fir” was measured with great care; the girth of the stem at 6¼ feet above the ground was often from 38 to 45 feet. One stem was 300 feet high, and without branches for the first 192 feet.
Pinus Strobus (in the eastern part of the United States of North America, especially on this side of the Mississippi, but also again in the Rocky Mountains, from the source of the Columbia to Mount Hood, from 43° to 54° north lat.), in Europe called the Weymouth Pine, and in North America the White Pine, commonly no more than 160 to 190 feet high, but several have been seen in New Hampshire of 250 and 266 feet.[PO]
Sequoia Gigantea (Endl.; the Condylocarpus, Sal.), of New California, like the Pinus trigona, about 300 feet high.
The nature of the soil and the conditions of heat and moisture, on which the nourishment of plants simultaneously depends, promote, it must be admitted, the development and the increase of the number of the individuals in a species; but the gigantic height attained by the stems of a few among the many nearly allied species of the same genus is not dependent on soil and climate but on a specific organization, on internal natural disposition, common alike to the vegetable and to the animal world. With the Araucaria imbricata of Chili, the Pinus Douglasii of the Columbia River, and the Sequoia gigantea of New California (245–300 feet) contrasts most strongly—not the Willow (Salix arctica) stunted by cold or mountain height, and only two inches high,—but a little phanerogamic plant in the beautiful climate of the southern tropical region, in the Brazilian province of Goyaz. The moss-like Tristicha hypnoides, of the Monocotyledonous family of the Podostemeæ, hardly attains the height of three lines. “While crossing the Rio Clairo in the province of Goyaz,” says an excellent observer, “I perceived on a stone a plant, the stalk of which was not more than three lines high, and which I considered at first to be a moss. It was, however, a phanerogamic plant, supplied with sexual organs like our oaks, and those gigantic trees which raised their majestic heads around.”[PP]
Besides the height of the stem, the length, breadth, and position also of the leaves and fruit, the aspiring or horizontal, almost umbellate ramification, the gradation of the colour from fresh or silver-greyish green to dark brown, give a peculiar physiognomical character to the Coniferæ. The acicular leaves of Pinus Lambertiana (Douglas) in North-Western America are five, those of the P. excelsa (Wallich) on the southern slope of the Himalaya near Katmandu, seven, and those of P. longifolia (Roxb.) on the mountain range of Cashmere, more than twelve inches long. Moreover, in one and the very same species, these acicular leaves vary in the most remarkable manner, from the combined influence of the nourishment derived from soil and air, and of the height above the level of the sea. I found these variations in the length of the leaves of our common wild pine (Pinus sylvestris) so great, while travelling in a west and east direction over an extent of 80° of longitude (more than 3040 miles) from the Scheldt, through Europe and Northern Asia, to Bogoslowsk, in the Northern Ural, and Barnaul beyond the Obi, that occasionally, deceived by the shortness and rigidity of the leaves, I have mistaken it for another species of pine, allied to the mountain fir, P. rotundata, Link, (Pinus uncinata, Ram.) These are, as Link correctly observes,[PQ] transitions to Ledebour’s P. sibirica of the Altai.
The delicate and pleasing green though deciduous foliage of the Ahuahuete (Taxodium distichum, Rich., Cupressus disticha, Linn.) on the Mexican plateau especially delighted me. In this tropical region the tree, swelling out to a portly bulk, and the Aztec name of which signifies “water-drum” (from atl, water, and huehuetl, drum), flourishes from 5750 to 7670 above the level of the sea, whilst it descends towards the plain in the marshy district (Cypress swamps) of Louisiana as far as 43° lat. In the southern States of North America the Taxodium distichum (Cyprès chauve), as well as in the lofty plains of Mexico, attains a height of 128 feet, with an enormous girth, the diameter being from 30 to nearly 40 feet, when measured near the ground.[PR] The roots, too, present a very remarkable phenomenon, for they have woody excrescences, which are sometimes of a conical and rounded, sometimes of a tabular shape, and project three and even nearly five feet above the ground. Travellers have compared these woody excrescences, in spots where they are numerous and frequent, to the grave-tablets of a Jewish churchyard. Auguste de St. Hilaire remarks, with much acuteness: “These excrescences of the bald cypress, which resemble boundary-posts, may be regarded as exostoses, and like these live in the air; adventitious buds would doubtless escape from them, if the nature of the tissue of the coniferous plants did not oppose itself to the development of those concealed germs that give birth to these kinds of buds.”[PS] In addition to the above, a remarkably enduring vitality is manifested in the roots of cone-bearing trees by the phenomenon which, under the name of “Effervescence,” (aftergrowth?) has attracted, in many ways, the attention of botanical physiologists, and which phenomenon, it appears, rarely displays itself in other dicotyledonous plants. The stumps of the felled white Pine, left in the ground, form, during a succession of several years, new layers of wood, and continue to increase in thickness, without throwing out shoots, branches, or leaves. The excellent observer Göppert believes, that this takes place solely through nourishment derived from the roots, which the extremity of the stem receives from a neighbouring living tree of the same species. The roots of the living tree he conceives are organically incorporated with those of the stump.[PT] Kunth, in his excellent new Lehrbuch der Botanik, is opposed to this explanation of a phenomenon, which was even known, though imperfectly, to Theophrastus.[PU] According to him, this process is perfectly analogous to that by which metallic plates, nails, carved letters, nay, even stags’ horns become imbedded within the body of wood. “The cambium, that is, the thin, walled cellular tissue, conducting muco-granular sap, from which new formations alone proceed, continues without any relation to the buds (being perfectly independent of them) to deposit new layers of wood on the outermost layer.”[PV]
The relation above alluded to, between the absolute height of the ground and the geographical as well as isothermal latitude, shows itself often, no doubt, when one compares the arborescent vegetation of the tropical part of the Andes chain with the vegetation of the north-west coast of America, or the banks of the Canadian lakes. The same remark was made by Darwin and Claude Gay in the southern hemisphere, when they, in their descent from the plateau of Chili, advanced towards Eastern Patagonia, and the Archipelago of Tierra del Fuego; here woods of Drymis Winteri, together with Fagus antarctica and Fagus Forsteri, cover every thing with long uniform rows in a northern and southern direction down to the low lands. Trifling deviations from the law of constant station-ratios between mountain height and geographical latitude, depending or local causes, not sufficiently investigated, occur even in Europe. I would call to mind the limits of altitude for the birch and common fir in a part of the Swiss Alps, on the Grimsel. The fir (Pinus sylvestris) flourishes there up to 6330; and the birch (Betula alba) up to 6906 feet; beyond them again there is a belt of stone pines (Pinus cembra), whose upper boundary is 7343 feet. The birch, in consequence, lies there between two belts of Coniferæ. According to the excellent observations of Leopold von Buch, and the more recent ones of Martius, who also visited Spitzbergen, the limits of the geographical distribution in the high Scandinavian north (in Lapland) are as follows: “The Fir extends to 70°; the White Birch (Betula alba) to 70° 40′; the Dwarf-Birch (B. nana) to 71° at least: Pinus cembra is entirely wanting in Lapland.”[PW]
As the length and the position of the acicular leaves define the physiognomic character of the coniferæ, this is still more designated by the specific difference of the leaf-breadth, and the parenchymatous development of the appendicular organs. Several species of Ephedra may be said to be almost leafless; but in Taxus, Araucaria, Dammara, (Agathis), and the Salisburia adiantifolia of Smith (Gingko biloba, Linn.), the breadth of the leaf gradually increases. I have here arranged the genera morphologically. Even the names of the species, as first chosen by botanists, indicate such an arrangement. Dammara orientalis of Borneo and Java, often 11 feet in diameter, was at first named loranthifolia: Dammara australis (Lamb.), in New Zealand, rising to 150 feet high, was originally named zamæfolia. Neither of these has acicular leaves, but “folia alterna oblongo lanceolata, opposita, in arbore adultiori sæpe alterna, enervia, striata.” The lower surface of the leaf is densely covered with stomata. These transitions of the appendicular system, from the greatest contraction to a broad leaf surface, possess, like every advance from simple to compound, both a morphological and a physiognomical interest.[PX] The short-stalked, broad, split leaf of the Salisburia (Kämpfer’s Ginkgo), has also the breathing pores (stomata) only on the inferior side. The original habitat of the tree is not known. It became distributed from the Chinese temples to the gardens of Japan, in consequence of the intercourse that existed in olden times between the congregations of Buddha.
I was a witness of the singularly painful impression, which the first sight of a pine-forest at Chilpanzingo made on one of our companions in travelling from a port in the South Sea through Mexico to Europe. Born in Quito, under the equator, he had never seen needle-leaved trees and folia acerosa. The trees appeared to him to be leafless, and because we were journeying towards the cold north, he thought he recognised already, in the extreme contraction of the organs, the impoverishing influence of the Pole. The traveller, whose impressions I am here describing, and whose name neither Bonpland nor myself can mention without regret, was an excellent young man, the son of the Marquis de Selvalegre, Don Carlos Montufar, whose noble and ardent love of freedom courageously led him, a few years later, to a violent, though not dishonourable, death, in the war of independence, waged by the Spanish colonies.