according to Dusén,’ their distribution is regulated by the amount of rainfall. In
the western parts of Tierra del Fuego, where the rainfall is heavy, the coast forest is
evergreen and is mainly composed of N. betuloides and Drimys Winteri; and
N. antarctica is only met with in the mountains. In the eastern part of Tierra del
Fuego, where the rainfall is slight, the latter species descends to sea-level and grows
in mixture with N. betuloides and N. pumilio.
In Western Patagonia, the evergreen forest predominates in the Archipelago and on the western side of the mountain range, where much rain falls and the prevailing winds are south-westerly ; whereas, on the eastern slopes of the mountains, where the climate is comparatively dry, the forests are composed of deciduous trees. According to Dusén, the deciduous-leaved forest is well seen at a point 30 miles up the River Aysen. In the inland region the ground is covered by a thin park-like forest, which is almost exclusively composed of one species, N. antarctica. This tree does not grow in such close masses as the European beech, and, owing to the absence of dense shade, there is a luxuriant undergrowth of herbs and shrubs. These park-like forests prevail up to 2300 feet. Above this elevation steppes occur, which are studded with small groves of N. pumilio, the ground being covered with mosses. At 3000 feet N. pumilio is only a low tree, which gradually becomes smaller as it ascends, until at 4300 feet it forms a stunted forest of dwarfed trees, with their branches interlaced together.
An earlier account of the Antarctic beeches is given by Sir J. D. Hooker,’ who states that N. antarctica strongly resembles the European beech in its deciduous leaves, form of trunk, and smooth bark. It ascends much higher at Cape Horn than N. betuloides, and is much the larger tree of the two when it is found growing at sea-level. N. betuloides, however, grows to a very large size about the Straits of Magellan, and being evergreen, is a marked feature of the scenery in winter, as its upper limit is sharply defined, and contrasts with the dazzling snow that covers the matted and naked branches of N. antarctica. Captain King® observed many trees of N. betuloides 3 to 4 feet in diameter, one being as large as 7 feet. He describes the wood as heavy and far too brittle for masts or even boat-hooks, but cutting up into tolerable planks. Hooker considered the timber of the deciduous species to be superior.
N. betuloides, while much commoner in the south, extends along the coast range as far north as Valdivia.‘ It is replaced in the Guaitecas Islands by N. Dombeyi and N. nitida.®
Nothofagus pumitio has been much confused with N. antarctica, of which it was made var. bicrenata by De Candolle. It is very distinct in both foliage and fruit. It extends from Chillan and Nahuelbuta in Chile southward to the Straits of Magellan, and is usually a shrub, constituting the scrubby growth which prevails
1 Princeton Univ. Exped. Patagonia, Botany 2, 10, 26 (1903-1906); and Engler, Bot. Jahrbüch. xxiv. 179 (1897).
2 Fl. Antarct. ii. 345.
3 Voyage of the "Adventure” and “Beagle,” i. 576 (1839). Ball, Notes of a Naturalist in S. America, 225, says that N. betuloides “has a thick trunk, commonly three or four feet in diameter, but nowhere attains any great height. Forty feet appeared to me the outside limit attained by any that I saw at Eden Harbour or elsewhere.”
4 Reiche, loc. cit.
5 Dusén, loc. cit.
