I will next name the form of Liliaceeous plants,[29] (Amaryllis, Ixia, Gladiolus, Pancratium) with their flag-like leaves and superb blossoms, of which Southern Africa is the principal country; also the Willow form[30], which is indigenous in all parts of the globe, and is represented in the elevated plains of Quito, (not in the shape of the leaves but in that of the ramification), by Schinus Molle; Myrtaceæ[31], (Metrosideros, Eucalyptus, Escallonia myrtilloides); Melastomaceæ[32], and the Laurel form[33].
It would be an enterprise worthy of a great artist to study the aspect and character of all these vegetable groups, not merely in hot-houses or in the descriptions of botanists, but in their native grandeur in the tropical zone. How interesting and instructive to the landscape painter[34] would be a work which should present to the eye, first separately and then in combination and contrast, the leading forms which have been here enumerated! How picturesque is the aspect of tree-ferns spreading their delicate fronds above the laurel-oaks of Mexico; or groups of plantains over-shadowed by arborescent grasses (Guaduas and Bamboos)! It is the artist’s privilege, having studied these groups, to analyse them: and thus in his hands the grand and beautiful form of nature which he would pourtray resolves itself, (if I may venture on the expression) like the written works of men, into a few simple elements.
It is under the burning rays of a tropical sun that vegetation displays its most majestic forms. In the cold north the bark of trees is covered with lichens and mosses, whilst between the tropics the Cymbidium and fragrant Vanilla enliven the trunks of the Anacardias, and of the gigantic fig trees. The fresh verdure of the Pothos leaves, and of the Dracontias, contrasts with the many-coloured flowers of the Orchideæ. Climbing Bauhinias, Passifloras, and yellow flowering Banisterias, twine round the trunks of the forest trees. Delicate blossoms spring from the roots of the Theobroma, and from the thick and rough bark of the Crescentias and the Gustavia.[35] In the midst of this profusion of flowers and fruits, and in the luxuriant intertwinings of the climbing plants, the naturalist often finds it difficult to discover to which stem the different leaves and flowers really belong. A single tree adorned with Paullinias, Bignonias, and Dendrobium, forms a group of plants which, if disentangled and separated from each other, would cover a considerable space of ground.
In the tropics vegetation is generally of a fresher verdure, more luxuriant and succulent, and adorned with larger and more shining leaves than in our northern climates. The “social” plants, which often impart so uniform and monotonous a character to European countries, are almost entirely absent in the Equatorial regions. Trees almost as lofty as our oaks are adorned with flowers as large and as beautiful as our lilies. On the shady banks of the Rio Magdalena in South America, there grows a climbing Aristolochia bearing flowers four feet in circumference, which the Indian boys draw over their heads in sport, and wear as hats or helmets.[36] In the islands of the Indian Archipelago the flower of the Rafflesia is nearly three feet in diameter, and weighs above fourteen pounds.
The great elevation attained in several tropical countries not only by single mountains but even by extensive districts, enables the inhabitants of the torrid zone—surrounded by palms, bananas, and the other beautiful forms proper to those latitudes—to behold also those vegetable forms which, demanding a cooler temperature, would seem to belong to other zones. Elevation above the level of the sea gives this cooler temperature even in the hottest parts of the earth; and Cypresses, Pines, Oaks, Berberries and Alders, (nearly allied to our own) cover the mountainous districts and elevated plains of Southern Mexico and the chain of the Andes at the Equator. Thus it is given to man in those regions to behold without quitting his native land all the forms of vegetation dispersed over the globe, and all the shining worlds which stud the heavenly vault from pole to pole.[37]
These and many other of the enjoyments which Nature affords are wanting to the nations of the North. Many constellations, and many vegetable forms,—and of the latter, those which are most beautiful, (palms, tree ferns, plantains, arborescent grasses, and the finely-divided feathery foliage of the Mimosas),—remain for ever unknown to them. Individual plants languishing in our hot-houses can give but a very faint idea of the majestic vegetation of the tropical zone. But the high cultivation of our languages, the glowing fancy of the poet, and the imitative art of the painter, open to us sources whence flow abundant compensations, and from whence our imagination can derive the living image of that more vigorous nature which other climes display. In the frigid North, in the midst of the barren heath, the solitary student can appropriate mentally all that has been discovered in the most distant regions, and can create within himself a world free and imperishable as the spirit by which it is conceived.
ANNOTATIONS AND ADDITIONS.
[1] p. 3.—“On the Chimborazo, eight thousand feet higher than Etna.”
Small singing birds, and even butterflies, are found at sea at great distances from the coast, (as I have several times had opportunities of observing in the Pacific), being carried there by the force of the wind when storms come off the land. In the same involuntary manner insects are transported into the upper regions of the atmosphere, 16000 or 19000 feet above the plains. The heated crust of the earth occasions an ascending vertical current of air, by which light bodies are borne upwards. M. Boussingault, an excellent chemist who, as Professor at the newly instituted Mining Academy at Santa Fé de Bogota, visited the Gneiss Mountains of Caraccas, in ascending to the summit of the Silla witnessed, together with his companion Don Mariano de Rivero, a phenomenon affording a remarkable ocular demonstration of the fact of a vertically ascending current. They saw in the middle of the day, about noon, whitish shining bodies rise from the valley of Caraccas to the summit of the Silla, which is 5400 (5755 E.) feet high, and then sink down towards the neighbouring sea coast. These movements continued uninterruptedly for the space of an hour, and the objects, which at first were mistaken for a flock of small birds, proved to be small agglomerations of straws or blades of grass. Boussingault sent me some of the straws, which were immediately recognised by Professor Kunth for a species of Vilfa, a genus which, together with Agrostis, is very abundant in the provinces of Caraccas and Cumana: it was the Vilfa tenacissima of our Synopsis Plantarum æquinoctialium Orbis Novi, T. i. p. 205. Saussure found butterflies on Mont Blanc, as did Ramond in the solitudes which surround the summit of the Mont Perdu. When Bonpland, Carlos Montufar, and myself, reached, on the 23d of June, 1802, on the eastern declivity of the Chimborazo, the height of 18096 (19286 E.) feet—a height at which the barometer sank to 13 inches 111⁄5 lines (14.850 English inches), we saw winged insects fluttering around us. We could see that they were Dipteras, resembling flies, but on a sharp ridge of rock (cuchilla) often only ten inches wide, between steeply descending masses of snow, it was impossible to catch the insects. The height at which we saw them was nearly the same at which the uncovered trachytic rock, piercing through the eternal snows, gave to our view, in Lecidea geographica, the last traces of vegetation. The insects were flying at a height of about 2850 toises (18225 E. feet), or about 2600 E. feet higher than Mont Blanc. Somewhat lower down, at about 2600 toises (10626 E. feet), also therefore within the region of perpetual snow, Bonpland had seen yellow butterflies flying very near the ground. According to our present knowledge the Mammalia which live nearest to the region of perpetual snow are in the Swiss Alps, the Marmot which sleeps through the winter, and a very small field-mouse (Hypudæus nivalis), described by Martins, which on the Faulhorn lays up a store of the roots of phænogamous alpine plants almost under the snow. (Actes de la Société Helvétique, 1843, p. 324.) The beautiful Chinchilla, of which the bright and silky fur is so much prized, is often supposed by Europeans to be an inhabitant of the high mountain regions of Chili: this, however, is an error; the Chinchilla laniger (Gray) only lives in the mild temperature of the lower zone, and is not found farther south than the parallel of 35°. (Claudio Gay, Historia fisica y politica de Chile, Zoologia, 1844, p. 91.)
While on our European Alps, Lecideas, Parmelias, and Umbilicarias form only a few coloured patches on the rocks which are not completely covered with snow, in the Andes, beautiful flowering phænogamous plants, first described by us, live at elevations of thirteen to fourteen thousand feet (13700 to nearly 15000 E.) We found there woolly species of Culcitium and Espeletia (C. nivale, C. rufescens, and C. reflexum, E. grandiflora, and E. argentea), Sida pichinchensis, Ranunculus nubigenus, R. Gusmanni with red or orange-coloured blossoms, the small moss-like umbelliferous plant Myrrhis andicola, and Fragosa arctioides. On the declivity of the Chimborazo the Saxifraga boussingaulti, described by Adolph Brongniart, grows beyond the limit of perpetual snow on loose boulders of rock, at 14796 (15770 E.) feet above the level of the sea, not at 17000, as stated in two estimable English journals. (Compare my Asie Centrale, T. iii. p. 262, with Hooker, Journal of Botany, vol. i. 1834, p. 327, and Edinburgh New Philosophical Journal, vol. xvii. 1834, p. 380.) The Saxifrage discovered by Boussingault is certainly, up to the present time, the highest known phænogamous plant on the surface of the earth.