[97]. p. 228—“The form of Grasses.”
The group of the arborescent grasses which Kunth has collected under the head of Bambusaceæ, in his great work on the plants collected by Bonpland and myself, constitutes one of the most beautiful adornments of tropical vegetation. Bambu, called also Mambu, occurs in the Malay language, although according to Buschmann merely as an isolated expression, the ordinary term in use being buluh, whilst the only name for this species of cane in Java and Madagascar is wuluh, voulou. The numbers of the genera and species included in this group have been extraordinarily increased by the industry of botanical travellers. It has been found that the genus Bambusa is entirely wanting in the New Continent, to which region, however, the gigantic Guaduas, discovered by us, and which attain a height of from 50 to 64 feet, together with the Chusquea, exclusively belong; that Arundinaria (Rich.) occurs in both continents, although differing specifically in each; that Bambusa and Beesha (Rheed.), occur in India and the Indian Archipelago; and that Nastus grows in the islands of Madagascar and Bourbon. With the exception of the high-climbing Chusquea, these forms morphologically replace each other in different parts of the earth. In the northern hemisphere far beyond the limits of the torrid region, in the valley of the Mississippi, the traveller is gladdened by the sight of a species of Bamboo, the Arundinaria macrosperma, formerly called also Miegia and Ludolfia. In the southern hemisphere, in the south of Chili, between the parallels of 37° and 42°, Gay found one of the Bambusaceæ more than 20 feet high (not a climbing, but a still undescribed arborescent self-supporting Chusquea), growing, mingled with Drymis Chilensis, in a region clothed with an uniform forest-covering of Fagus obliqua.
Whilst in India the Bambusa flowers so frequently that in Mysore and Orissa the seeds are mixed with honey, and eaten like rice,[[QG]] in South America the Guadua blossoms so very seldom that in the course of four years we were only twice able to procure the flowers; once on the solitary banks of the Cassiquiare, the arm connecting the Orinoco with the Rio Negro and the Amazon, and again in the province of Popayan, between Buga and Quilichao. It is a very striking fact that some plants grow with the greatest vigour in certain localities without flowering; as is the case with the European olive-trees introduced into America centuries ago, and growing between the tropics, near Quito, at elevations of about 9600 feet above the level of the sea; and in like manner the walnuts, hazel-nut bushes, and the fine olive-trees (Olea Europea) of the Isle of France.[[QH]]
As some of the Bambusaceæ (arborescent grasses) advance into the temperate zone, so also they do not suffer in the torrid zone from the temperate climate of mountain districts. They are certainly more luxuriant as social plants between the sea-shore and elevations of about 2558 feet in the Province de las Esmeraldas, west of the volcano of Pichincha, where Guadua angustifolia (Bambusa Guadua of our Plantes équinoxiales, t, i. tab. xx) generates in its interior large quantities of the siliceous Tabaschir (Sanscrit tvakkschira, cow-milk). We saw the Guadua advance in the pass of Quindiu, in the chain of the Andes, to a height of 5755 feet above the level of the sea, as determined by barometric measurements. Nastus borbonicus has been called a true Alpine plant by Bory de St. Vincent, and according to him it does not descend lower than 3840 feet on the declivity of the volcano in the island of Bourbon. This appearance or the repetition at great elevations of certain forms belonging to torrid plains calls to mind the group of Alpine palms (Kunthia montana, Ceroxylon andicola, and Oreodoxa frigida) of which I have already spoken, and a grove of Musaceæ (Heliconia, perhaps Maranta), 16 feet high, which I found growing isolated on the Silla de Caracas, at a height of more than 7000 feet above the level of the sea.[[QI]] While the form of gramineæ, with the exception of some few herbaceous dicotyledons, constitutes the highest phanerogamic zone on the snow-crowned summits of mountains, so the grasses mark the boundary of phanerogamic vegetation in a horizontal direction, towards the northern and southern polar regions.
Many admirable general results, no less than a great mass of important materials, have been yielded to the geography of plants by my young friend, Joseph Hooker, who, after having but recently returned with Sir James Boss from the frozen antarctic regions, is now engaged in exploring the Thibetian Himalaya. He draws attention to the fact that phanerogamic flowering plants (grasses) advance 17½° nearer to the north than to the south pole. In the Falkland Islands, near the thick knots of Tussac grass, Dactylis cæspitosa, Forster. (a Festuca, according to Kunth), and in Tierra del Fuego, under the shade of the birch-leaved Fagus antarctica, there grows the same Trisetum subspicatum, which spreads over the whole range of the Peruvian Andes, and across the Rocky Mountains, to Melville Island, Greenland, and Iceland, and is also found in the Swiss and Tyrolese Alps as well as in the Altai, in Kamtschatka, and in Campbell’s Island, south of New Zealand, extending therefore over 127 degrees of latitude, or from 54° south to 72° 50′ north lat. “Few grasses,” says Joseph Hooker,[[QJ]] “have so wide a range as Trisetum subspicatum (Beauv.), nor am I acquainted with any other arctic species which is equally an inhabitant of the opposite polar regions.” The South Shetland Islands, which are separated by Bransfield Straits from d’Urville’s “Terre de Louis-Philippe” and from Peak Haddington, a volcano, 7046 feet high, and situated in 64° 12′ south lat., have recently been visited by Dr. Eights, a botanist from the United States. He found there (probably in 62° or 62¼° south lat.) a small grass, Aira antarctica,[[QK]] which is “the most antarctic flowering plant hitherto discovered.”
Even in Deception Island, belonging to the same group, 62° 50′, only lichens are met with, and no longer any species of grass; and in like manner further south-east, in Cockburn’s Island (64° 12′) near Palmer’s Land, only Lecanoras, Lecideas, and five foliaceous Mosses, among which is our German Bryum argenteum, were gathered. “This appears to be the Ultima Thule of antarctic vegetation,” for further south even terrestrial cryptogamia are wanting. In the great bay formed by Victoria Land, on a small island lying opposite to Mount Herschel (in 71° 49′ lat.), and on Franklin Island, 92 miles north of the volcano, Erebus, (12,366 feet in height), and in 76° 7′ south lat., Hooker found no trace of vegetation. In extreme northern latitudes, the distribution of even the higher organisms is very different; for here phanerogamic plants advance 18½° nearer to the pole than in the southern hemisphere. Walden Island (80½° north lat.) possesses still ten species of phanerogamia. Antarctic phanerogamic vegetation is also poorer in species at equal distances from the pole; thus Iceland has five times more phanerogamia than the southern group of Auckland and Campbell Islands, but the uniform vegetation of the antarctic regions is, from climatic causes, both more succulent and more luxuriant.[[QL]]
[98]. p. 229—“Ferns.”
If we estimate the whole number of the cryptogamia hitherto described at 19,000 species, as has been done by Dr. Klotzsch, a naturalist possessing a profound acquaintance with the Agamic plants, we shall have for Fungi 8000 (of which Agarici constitute the eighth part); for Lichens, according to J. von Flotow of Hirschberg, and Hampe of Blankenburg, at least 1400; for the Algæ 2580; for Mosses and Liverworts, according to Carl Müller of Halle, and Dr. Gottsche of Hamburgh, 3800; and for Ferns 3250. For this last important result we are indebted to the profound investigations made by Professor Kunze of Leipzig, on this group of plants. It is a striking fact that the family of the Polypodiaceæ alone includes 2165 of the whole number of described Filices, whilst other forms, as the Lycopodiacæ and Hymenophyllaceæ, number only 350 and 200. There are therefore nearly as many described species among Ferns as among Grasses.
It is singular that no mention of the beautiful arborescent ferns is to be found in the classic authors of antiquity, Theophrastus, Dioscorides, and Pliny; while, from the information given by the companions of Alexander, Aristobulus, Megasthenes, and Nearchus, reference is made[[QM]] to Bamboos, “quæ fissis internodiis lembi vice vectitabant navigates;” to the Indian trees “quarum folia non minora clypeo sunt;” to the Fig-tree which takes root from its branches, and to Palms, “tantæ proceritatis, ut sagittis superjici nequeant.” I find the first mention of arborescent ferns in Oviedo.[[QN]] “Among ferns,” says this experienced traveller, who had been appointed by Ferdinand the Catholic, Director of the Goldwashings in Haiti, “there are some which I class with trees, because they are as thick and high as Pine-trees. (Helechos que yo cuento por arboles, tan gruesos como grandes pinos y muy altos). They mostly grow among the mountains and where there is much water.” This estimate of their height is exaggerated, for in the dense forests near Caripe even our Cyathea speciosa only attains a height of 32 to 37 feet; and an admirable observer, Ernst Dieffenbach, did not see in the most northern of the three islands of New Zealand any trunks of Cyathea dealbata exceeding 42½ feet. In the Cyathea speciosa and the Meniscium of the Chaymas missions, we observed in the midst of the most shady part of the primeval forest, that the scaly stems of some of the most luxuriantly developed of these trees were covered with a shining carbonaceous powder, which appeared to be owing to a singular decomposition of the fibrous parts of the old leaf stalks.[[QO]]
Between the tropics, where, on the declivities of the Cordilleras, climates are superimposed in strata, the true region of arborescent ferns lies between about 3200 and 5350 feet above the level of the sea. In South America and in the Mexican highlands they seldom descend lower towards the plains than 1280 feet. The mean temperature of this happy region is between 64°.6 and 70°.8 Fahr. It reaches the lowest stratum of clouds (which floats the nearest to the surface of the sea and the plain), and it therefore enjoys uninterruptedly a high degree of humidity, together with a great equality in its thermal relations.[[QP]] The inhabitants, who are of Spanish descent, call this region “Tierra templada de los helechos.”