Page:The Botany of the Antarctic Voyage.djvu/383

From Wikisource
Jump to navigation Jump to search
This page has been validated.
Falklands, etc.]
FLORA ANTARCTICA.
347

bourhood, the Evergreen Beech grows in the greatest abundance and reaches a very large size. Trees of this species three feet in diameter, are abundant; of four feet there are many; and there is one tree (perhaps the very same noticed by Commodore Byron), which measures seven feet in diameter for seventeen feet above the roots, and then divides into three large branches, each of which is three feet through. This venerable tree seemed to be sound, but from our experience of several others that were cut down, might be expected to prove rotten in the centre. This tendency to decaying in the heart may be attributed to the coldness of the schistose sub-soil upon which the trees are rooted, as well as the perpetual moisture of the climate."

The wood of these trees Capt. King describes as being heavy and far too brittle for masts, or even boat-hook staves; but it cuts up into tolerable planks, which, if seasoned, might serve for ship-building. During our sojourn in Hermite Island, Capt. Ross caused several thousand small trees, of both species, to be felled and barked; these we transported to the Falkland Islands, in which tree-less country they were highly prized for roofing houses, &c. The deciduous species appeared to afford the better wood of the two.

A more striking contrast between two so very closely allied plants, cannot well be imagined, than between F. Antarctica and F. betuloides, arising from the evergreen foliage of the latter being of a totally different texture and aspect from that of the former. Surely so strongly marked a difference between otherwise very nearly allied species, growing side by side under perfectly similar conditions, is a strong argument in favour of their being originally separate creations. We see, too, how the adaptation of particular forms of vegetation to certain climates, even in this remote quarter of the globe, is exemplified in these trees; though both do grow together abundantly, they still have their preferences, the evergreen glossy foliage prevailing on the western coast, where the climate is damp and equable, whilst the deciduous-leaved plant seeks the heights more exposed to the vicissitudes of the weather, or the drier eastern parts of Fuegia, where the F. betuloides will not succeed. So it is with us in Great Britain; our glossy-leaved evergreens, whether native or introduced, thrive best in the climate of the west coast, where the summers are colder, the winters wanner, and all the seasons more humid than they are on the east. The third species of Fagus, the F. obliqua, replaces F. Antarctica in South Chili, occupying the flanks of the Andes, between the altitudes of 1,000 and 5,000 feet, where it is the prevailing forest-tree. It appears to inhabit the level of the sea in the parallel of the Strait of Magalhaens, and is probably the third species of Beech alluded to by Capt. King (1. c. p. 576), for that voyager does not seem to have distinguished the F. Pumilio as a species.

The accompanying cut will explain better than words, the order of succession in latitude and in elevation that South American Fagi follow. Their southern ranges may be ascertained with tolerable precision, the exact altitude they attain in the two northern positions is more doubtful. The positions taken are, commencing from the southward, 1st, Hermite Island, lat, 56°; 2nd, Strait of Magalhaens, lat. 54°; 3rd, Antuco in Chili, lat. 36° 40'. The upper curve indicates the lower level of perpetual snow; the others, the upper limit of the tree whose name is found immediately under.

From the want of a suite of specimens I cannot speak with much confidence of the Chilian species, F. alpina and F. Pumilio, the first appears, from the plate and description, a variety of F. betuloides, and, from occupying the position that F. betuloides would hold relatively to the others in South Chili, I have introduced it as such into the cut. The F. Pumilio is even more probably a variety of F. Antarctica. Both are said to occupy great heights in South Chili, the latter indeed only existing there as a stunted tree. There are still two other South Chilian species, F. procera, P. and E., and F. Dombeyi[1] Mirb.; they inhabit the level of the sea in the parallel of 41°. The first I am inclined to regard as a variety of F. obliqua, or rather a large-leaved state of that plant descending to the coast; the second is a similar form of F. betuloides. If my supposition prove correct, both species afford examples


  1. This is one kind of "Roble" of Capt. King's Narrative (p. 280); in speaking of the woods of Chiloe, he says, "Roble, (Fagus obliqua, Mirb.), is a large tree, and, from the durable quality of its timber, considered the