In the South of Europe and in North America, Hops from among the Urticeæ, and the species of Vitis from among the Ampelideæ, belong to the class of twining climbers, and between the tropics we find climbing Grasses or Gramineæ. We have seen in the plains of Bogota, in the pass of Quindiu, in the Andes, and in the Quina-producing forests of Loxa, a Bambusacea allied to Nastus, our Chusquea scandens, twine round massive and lofty trunks of trees adorned at the same time with flowering Orchideæ. The Bambusa scandens (Tjankorreh), which Blume found in Java, belongs probably either to the genus Nastus or to that of Chusquea, the Carrizo of the Spanish settlers. Twining plants appear to me to be entirely absent in the Pine-woods of Mexico, but in New Zealand, besides the Ripogonum parviflorum of Robert Brown, (a climber belonging to the Smilaceæ which renders the forests almost impenetrable), the sweet-smelling Freycinetia Banksii, which belongs to the Pandaneæ, twines round a gigantic Podocarpus 220 English feet high, the P. dacryoides (Rich), called in the native language Kakikatea. (Dieffenbach, Travels in New Zealand, 1843, Vol. i. p. 426.)
With climbing Gramineæ and Pandaneæ are contrasted by their beautiful and many-coloured blossoms the Passifloras (among which, however, we even found an arborescent self-supporting species, Passiflora glauca, growing in the Andes of Popayan, at an elevation of 9840 French (10487 English) feet);—the Bignoniaceæ, Mutisias, Alströmerias, Urvilleæ, and Aristolochias. Among the latter our Aristolochia cordata has a crimson-coloured flower of 17 English inches diameter! “flores gigantei, pueris mitræ instar inservientes.” Many of these twining plants have a peculiar physiognomy and appearance produced by the square shape of their stems, by flattenings not caused by any external pressure, and by riband-like wavings to and fro. Cross sections of Bignonias and Banisterias shew cruciform or mosaic figures produced by the mutual pressure and interpenetration of the stems which twine around each other. (See very accurate drawings in Adrien de Jussieu’s Cours de Botanique, p. 77-79, fig. 105-108.)
[26] p. 27.—“The form of Aloës.”
To this group of plants, characterised by so great a similarity of physiognomy, belong; Yucca aloifolia, which extends as far north as Florida and South Carolina; Y. angustifolia (Nutt.) which advances as far as the banks of the Missouri; Aletris arborea; the Dragon-tree of the Canaries and two other Dræcænas from New Zealand; arborescent Euphorbias; Aloë dichotoma (Linn.) (formerly the genus Rhipidodendrum of Willdenow); and the celebrated Koker-boom of Southern Africa with a trunk twenty-one feet high and above four feet thick, and a top of 400 (426 Engl.) feet in circumference. (Patterson, Reisen in das Land der Hottentotten und der Kaffern, 1790, S. 55.) The forms which I have thus brought together belong to very different families: to the Liliaceæ, Asphodeleæ, Pandaneæ, Amaryllideæ, and Euphorbiaceæ; all, however, with the exception of the last, belonging to the great division of the Monocotyledones. A Pandanea, Phytelephas macrocarpa (Ruiz,) which we found in New Granada on the banks of the Magdalena, with its pinnated leaves, quite resembles in appearance a small palm-tree. This Phytelephas, of which the Indian name is Tagua, is besides, as Kunth remarks, the only one of the Pandaneæ found (according to our present knowledge) in the New Continent. The singular Agave-like and at the same time very tall-stemmed Doryanthes excelsa of New South Wales, which was first described by the acutely observing Correa de Serra, is an Amaryllidea, like our low-growing Narcissuses and Jonquils.
In the Candelabra shape of plants of the Aloë form, we must not confound the branches of an arborescent stem with flower-stalks. It is the latter which in the American Aloë (Agave Americana, Maguey de Cocuyza, which is entirely wanting in Chili) as well as in the Yucca acaulis, (Maguey de Cocuy) presents in the rapid and gigantic development of the inflorescence a candelabrum-like arrangement of the flowers which, as is well known, is but too transient a phenomenon. In some arborescent Euphorbias, on the other hand, the physiognomic effect is given by the branches and their division, or by ramification properly so called. Lichtenstein, in his “Reisen im südlichen Africa” (Th. i. S. 370), gives a vivid description of the impression made upon him by the appearance of a Euphorbia officinarum which he found in the “Chamtoos Rivier,” in the Colony of the Cape of Good Hope; the form of the tree was so symmetrical that the candelabrum-like arrangement was regularly repeated on a smaller scale in each of the subdivisions of the larger branches up to 32 English feet high. All the branches were armed with sharp spines.
Palms, Yuccas, Aloes, tall-stemmed Ferns, some Aralias, and the Theophrasta where I have seen it growing luxuriantly, different as they are in the structure of their flowers, yet offer to the eye in the nakedness (absence of branches) of their stems, and in the ornamental character of their tops or crowns, a certain degree of physiognomic resemblance.
The Melanoselinum decipiens (Hofm.), which is sometimes upwards of 10 or 12 feet high, and which has been introduced into our gardens from Madeira, belongs to a peculiar group of arborescent umbelliferous plants to which Araliaceæ are otherwise allied, and with which other plants which will doubtless be discovered in course of time will be associated. Ferula, Heracleum, and Thapsia, do indeed attain a considerable height, but they are still herbaceous plants. Melanoselinum is still almost entirely alone as an umbelliferous tree; Bupleurum (Tenonia) fruticosum (Linn.) of the shores of the Mediterranean; Bubon galbanum of the Cape, and Crithmum maritimum of our sea-shores, are only shrubs. On the other hand, the tropical zone, in which, according to the old and very just remark of Adanson, Umbelliferæ and Cruciferæ are almost entirely wanting in the plains, presented to us on the high ridges of the American Andes the smallest and most dwarf-like of all umbelliferous plants. Among 38 species of plants which we collected at elevations where the mean temperature is below 10° Reaumur (54°.5 Fah.), there vegetate almost like mosses, and as if they made part of the rock and of the often frozen earth, at an elevation of 12600 (13430 English) feet above the level of the sea, Myrrhis andicola, Fragosa arctioïdes, and Pectophytum pedunculare, intermingled with which there is an equally dwarfed Alpine Draba. The only umbelliferous plants growing in the low grounds within the tropics observed by us in the New Continent were two species of Hydrocotyle (H. umbellata and H. leptostachya) between Havannah and Batabano; therefore at the extreme limits of the torrid Zone.
[27] 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.