Edwards's Botanical Register/Appendix to the first twenty-three volumes/A sketch of the vegetation of the Swan River Colony
A SKETCH OF THE VEGETATION
SWAN RIVER COLONY.
The frequent arrival of seeds from this Colony, the excellent state in which they are received, and the facility with which further supplies can be procured, appear to render some Botanical account of this remarkable country a desirable appendage to a work which, like the Botanical Register, forms an original record of new plants introduced, or worthy of introduction, to our Gardens. A publication of the more remarkable or beautiful species will tend to prevent double names, which would otherwise be likely to find their way into collections, in consequent of species being named by difference Botanists independently of each other; and this is in itself an object, the attainment of which is of considerable importance. Moreover the purchasers of plants will often be able, by a reference to this sketch, to ascertain, by the names under which Swan River plants are offered for sale, whether particular species are worth possession, either for the sake of their beauty or singularity.
The only systematical account of the Swan River Flora which has yet appeared is Baron Hugel's Enumeration,* but as nothing has been printed of that valuable work, beyond a single number, published in 1837, it is to be feared that we are not likely to see a continuation of it. There are however several scattered notices of Swan River plants by Dr. Endlicher,† one of the principal contributors to the Enumeration, and occasional descriptions have appeared in the
† Novarum Stirpium Decades, editæ a Museo Cæsarea Palatino Vindobonensi. Ni. 1–4. Maii, 1839. 8vo.
Stirpium Australasicarum herbarii Hügeliani Decades tres. Vindob. Dec. 1838, 4to.
Botanical Register and Botanical Magazine; some of the Proteaceæ have also been described in Brown's Supplement.* If to these sources of information we add a short notice of the vegetation of the country by Dr. Brown,† and a similar paper by the late Mr. Charles Frazer,‡ there is little further to notice concerning the published accounts of the Botany of this part of the world.
The materials from which the following sketch has been drawn up are the foregoing documents, and an herbarium of about 1000 species, formed by the communications of Mr. James Drummond, now resident in the Colony, Captain James Mangles, R.N., R. Mangles, Esq., Mr. Toward, Gardener to Her Royal Highness the Duchess of Gloucester, and N. B. Ward, Esq. of Wellclose Square, to all whom I beg to express my thanks for the assistance they have afforded me. Some information regarding the climate and soil has also been derived from papers in the Journal of the Geographical Society, and from a memoir upon Western Australia by Dr. Milligan, which was published in the Madras Journal for October 1837.
The Swan River Colony is stationed on the South-west coast of New Holland, about two degrees nearer the tropic than Sydney, on the opposite coast, the mouth of the river being nearly in 32° S. lat., whence it runs gradually in a north-easterly direction. The Colony itself is situated upon both sides of the river, and extends as far south as the Murray in lat. 32°. 33'. According to Dr. Milligan the entire area of the Colony is about 50 miles by 30; but there is no evidence to shew whether all the plants hereafter to be noticed were collected within these narrow limits.
The country is described as being usually of the open forest description, consisting of undulating plains, covered with a great profusion of plants; three-fourths of the trees belonging to the genus Eucalyptus. It is broken by the
* Supplementum primum Prodromi Floræ N. Holl. Lond. 1830. 8vo.
limestone mountains of the Darling range, which rise about 2000 feet above the sea, and are covered with evergreen trees.
Dr. Milligan observes, that "the soil is of three different kinds—1st, sandy—2nd, alluvial—3rd, red loam; the first is found near the coast, and, though unpromising in appearance, trees, shrubs, and grasses grow on it abundantly, and with the assistance of manure excellent esculent vegetables are obtained from it, as the valuable gardens in the farms of Perth and Freemantle sufficiently testify. The second, or alluvial, is in extensive flats, and produces admirable crops of wheat, barley, oats, &c. without any assistance from manure. The third, or red loam, which is met with on the high ground on the banks of the rivers, produces the same crops as the alluvial, but requires the assistance of manure. There is a great deal of subterraneous moisture, which appears to be retained by a sub-soil of clay, which is to be met with at an average depth of five or six feet."
Mr. Frazer made the same remark as to the abundance of water near the surface. He says that he was very much astonished at the beautiful dark-green and vigorous appearance of the trees, considering that the season had been unusually dry; but he found the cause to depend upon the great quantity of springs with which the country abounds. On penetrating two feet into the earth he found the soil perfectly moist, and he felt confident that if he had penetrated a foot deeper he should have found water.
Concerning the climate, which Mr. Frazer describes as "the most delightful he ever experienced", we have some good information from Dr. Milligan. The hottest months are December, January and February; the greatest heat observed in four years was 106° Fahr. in January, 1831, and the least was 33° in July of the same year. The mean of the hottest month was 78°, and of the coldest 54°.84. Between nine and ten inches of rain fell in July, 1830, and June, 1833, while in January there was less than an inch; the summer months being hot and dry, the winter very wet and comparatively cold; the whole amount of rain that fell in 1830 was 32.142 inches, and, in 1833, 26.925 inches.
Among the introduced plants we are informed of the following facts. Along the banks of the rivers may be seen fields of wheat, barley, oats, peas, potatoes, turnips, pumpkins, Indian wheat, &c. intermixed with fine pasture land. The sandy soil is covered with coarse herbage, on which cattle thrive remarkably well; on the good soil, about sixteen kinds of grasses are met with, amongst which anthistiria australis, the kangaroo grass, is conspicuous. The gardens furnish most kinds of edible vegetables in great abundance; some of which may be obtained in all seasons. Amongst these are cabbages, endive, beet, parsley, cresses, leaks, onions, radishes, carrots, knol-kohl, parsnips, turnips, artichokes, vegetable marrow, and cauliflower; also cucumbers, pumpkins, water cresses, tomatos, capsicums; with musk melon, rock melon, and water melon in great plenty and perfection. The fruits now thriving are the grape, fig, peach, almond, apple, pear, strawberry, sloe, plum (several varieties), olive, the common and white mulberry, pine apple, plantain, sugar cane, Cape gooseberry; besides which several ripen, which, in colder countries, never come to perfection: such as lemons, citrons, and oranges. From all which data we may conclude that the climate of Swan River is like that of the South of Italy; and that while any of the native plants may be expected to thrive in the open air in England during the summer, none are likely to bear our winters except the mountain plants, and those only in the South of England.
The more conspicuous plants which greatly contribute to give a character to the landscape are, according to Brown, Kingia australis, a species of Xanthorhœa, a Zamia nearly allied to and perhaps not distinct from Z. spiralis of the East coast, although it is said frequently to attain the height of thirty feet; a species of Callitris; one or two of Casuarina; an Exocarpus, probably not different from E. cupressiformus; and Nuytsia floribunda. The latter (Tab IV.), which bears a profusion of yellow flowers, and is said to attain the stature of a small Orange tree, is a most curious instance of a plant, belonging to the parasitical order Loranthaceæ, growing in the ground. The Xanthorhœa above mentioned, is described by Frazer as being associated with gigantic specimens of a Banksia he calls grandis, and, with Zamia spiralis, thirty feet high, which it rivals in dimensions, forming groups that impart to some places a character perfectly tropical. The natural orders which most abound in the Colony are chiefly composed of species peculiar to this part of Australia; the richest in species are Myrtaceæ, especially the curious and beautiful tribe of Chamælaucieæ, Fabaceæ or Leguminosæ, Rutaceæ, Lasiopetaleæ, Droseraceæ, Pittosporaceæ, Compositæ, Epacridaceæ, Goodeniaceæ, Styidiaceæ, Proteaceæ, Hæmodoraceæ, and Orchidaceæ; concerning each of which it is necessary to offer some special observations.