Note 27 — PHYSIOGNOMY OF PLANTS.

p. 27—“The form of Gramineæ.”

The group of arborescent grasses which Kunth, in his able treatise on the plants collected by Bonpland and myself, has combined under the name of Bambusaceæ, is among the most beautiful adornments of the tropical world. (Bambu, also called Mambu, is a word in the Malay language, but appears according to Buschmann to be of doubtful origin, as the usual Malay expression is buluh, in Java and Madagascar wuluh, voulu.) The number of genera and species which form this group has been extraordinarily augmented by the zeal of botanists. It is now recognised that the genus Bambusa is entirely wanting in the New Continent, to which on the other hand Guadua, from 50 to 60 French or about 53 to 64 English feet high, discovered by us, and Chusquea, exclusively belong; that Arundinaria (Rich) is common to both continents, although the species are different; that Bambusa and Beesha (Rheed.) are found in India and the Indian Archipelago, and Nastus in the Island of Bourbon, and in Madagascar. With the exception of the tall-climbing Chusquea the forms which have been named may be said to replace each other morphologically in the different parts of the world. In the northern hemisphere, in the valley of the Mississipi, the traveller is gratified, long before reaching the tropics, with the sight of a form of bamboo, the Arundinaria macrosperma, formerly called also Miegia, and Ludolfia. In the Southern Hemisphere Gay has discovered a Bambusacea, (a still undescribed species of Chusquea, 21 English feet high, which does not climb, but is arborescent and self-supporting) growing in southern Chili between the parallels of 37° and 42° S. latitude; where, intermixed with Drymis chilensis, a uniform forest covering of Fagus obliqua prevails.

While in India the Bambusa flowers so abundantly that in Mysore and Orissa the seeds are mixed with honey and eaten like rice, (Buchanan, Journey through Mysore, Vol. ii. p. 341, and Stirling in the Asiat. Res. Vol. xv, p. 205) in South America the Guadua flowers so rarely, that in four years we were only twice able to procure blossoms; once on the unfrequented banks of the Cassiquiare, (the arm which connects the Orinoco with the Rio Negro and the Amazons River,) and once in the province of Popayan between Buga and Quilichao. It is striking to see plants in particular localities grow with the greatest vigour without producing flowers: it is thus with European olive trees which have been planted for centuries between the tropics near Quito, 9000 (about 9590 English) feet above the level of the sea, and also in the Isle of France with Walnut-trees, Hazel-nuts, and, as at Quito, olive trees (Olea europea): see Bojer, Hortus Mauritianus, 1837, p. 291.

As some of the Bambusaceæ (arborescent grasses) advance into the temperate zone, so within the tropics they do not suffer from the temperate climate of the mountains. They certainly grow more luxuriantly as social plants from the sea coast to the height of about 2560 English feet; for example, in the province de las Esmeraldas, west of the Volcano of Pichincha, where Guadua angustifolia (Bambusa Guadua in our Plantes équinoxiales, T. i. Tab. xx.) produces in its interior much of the siliceous Tabaschir (Sanscrit tvakkschira, ox-milk). In the pass of Quindiu we saw the Guadua growing at an elevation which we found by barometric measurement to be 5400 (5755 English) feet above the level of the Pacific. Nastus borbonicus is called by Bory de St. Vincent a true Alpine plant; he states that it does not descend lower on the declivity of the Volcano in the Island of Bourbon than 3600 (3837 English) feet. This recurrence or repetition as it were at great elevations of the forms characteristic of the hot plains, recalls the mountain group of palms before pointed out by me (Kunthia Montana, Ceroxylon andicola, and Oreodoxa frigida), and a grove or thicket of Musaceæ sixteen English feet high (Heliconia, perhaps Maranta), which I found growing isolated at an elevation of 6600 (7034 English) feet, on the Silla de Caraccas. (Rélation hist. T. i. p. 605-606.) As, with the exception of a few isolated herbaceous dicotyledones, grasses form the highest zone of phænogamous vegetation round the snowy summits of lofty mountains, so also, in advancing in a horizontal direction towards either pole of the Earth, the phænogamous vegetation terminates with grasses.

To my young friend Joseph Hooker, who, but just returned with Sir James Ross from the frozen antarctic regions, is now exploring the Thibetian portion of the Himalaya, the geography of plants is indebted not only for a great mass of important materials, but also for excellent general deductions. He calls attention to the circumstance that phænogamous flowering plants (grasses) approach 17½° nearer to the Northern than to the Southern pole. In the Falkland Islands near the thick masses of Tussack grass (Dactylis cæspitosa, Forster, according to Kunth a Festuca), and in Tierra del Fuego or Fuegia, under the shade of the birch-leaved Fagus antarctica, there grows the same Trisetum subspicatum which extends over the whole range of the Peruvian Cordilleras, and over the Rocky Mountains to Melville Island, Greenland, and Iceland, and which is also found in the Swiss and Tyrolese Alps, in the Altai mountains, in Kamtschatka, and in Campbell Island, south of New Zealand; therefore, from 54° South to 74½° North latitude, or through 128½° of latitude. “Few grasses,” says Joseph Hooker, in his Flora Antarctica, p. 97, “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 divided by Bransfield Strait from D’Urville’s Terre de Louis Philippe and the Volcano of Haddington Peak, situated in 64° 12´ South latitude and 7046 English feet high, have been very recently visited by a Botanist from the United States of North America, Dr. Eights. He found there (probably in 62° or 62¼°, S. latitude) a small grass, Aira antarctica (Hooker, Icon. Plant. Vol. ii. Tab. 150) which is “the most antarctic flowering plant hitherto discovered.”

In Deception Island, of the same group, S. lat. 62° 50´, lichens only are found, and not a single species of grass; and so also farther to the south-east, in Cockburn Island (lat. 64° 12´), near Palmer’s Land, there were only found Lecanoras, Lecideas, and five Mosses, among which was our German Bryum argenteum: “this seems to be the ultima Thule of antarctic vegetation.” Farther to the south, land-cryptogamic, as well as phænogamic, vegetation is entirely wanting. In the great bay formed by Victoria Land, on a small island which lies opposite to Mount Herschel (S. lat. 71° 49´), and in Franklin Island, 92 geographical miles North of the great volcano Mount Erebus, 12400 English feet high (latitude 76° 7´ South), Hooker found not a single trace of vegetable life. It is quite different in respect to the extension even of the forms of higher vegetable organisation in the high northern latitudes. Phænogamous plants there approach 18½° nearer to the pole than in the southern hemisphere: Walden Island (N. lat. 80½°) has still ten species. The antarctic phænogamous vegetation is also poorer in species at corresponding distances from the pole (Iceland has five times as many flowering plants as the southern group of Auckland and Campbell Islands), but this less varied antarctic vegetation is from climatic reasons more luxuriant and succulent. (Compare Hooker, Flora antarctica, p. vii., 74, and 215, with Sir James Ross, Voyage in the Southern and Antarctic Regions, 1839-1843, Vol. ii. p. 335-342.)