DUSEN I THE VEGETATION OF WESTERN PATAGONIA. 33 



The community of evergreen beeches occupies a narrow, but very long 

 strip of land on the western side of the Cordillera. In the south it 

 expands over the western and southwestern portions of the Magellan dis- 

 trict, reaching its southern limit only at Cape Horn. Northward, it 

 extends through the whole of southern Chili, its total range north and 

 south comprising no less than 18 degrees of latitude, equal to about 2000 

 kilometers, or 1200 English miles. 



The space occupied by the community of deciduous beeches on the 

 western side of the Cordillera is far less extensive. At its southernmost 

 point, on or near the Straits of Magellan, it is not quite homogeneous, 

 but is intermingled with some intruders from the community of evergreen 

 beeches, which here unexpectedly extend far eastward. In the southern 

 part of Fuegia also, at least along the eastern section of the Beagle 

 Channel, both of these communities are intermingled, though even here, 

 between the Rio Grande and the large firth-like lake, Lago Fagnano, the 

 former is quite typical. Farther north and already in northern Patagonia, 

 the character of this community of plants is somewhat modified by the 

 accession of new elements, the most important being Libocedrus chilensis 

 Endl., though to what extent, I was not in a position to determine. 



The steppe vegetation, on the whole, is very uniform throughout the 

 entire length of the area which it occupies. In northern Patagonia this 

 area is evidently very narrow, but towards the south it expands more and 

 more, extending in Fuegia, and probably in southern Patagonia also, 

 quite to the Atlantic coast. Many species range over the whole of the 

 Patagonian steppe, extending also to the Fuegian. To give one instance 

 only, Festuca gracillima, which is so characteristic of the small steppes in 

 the upper Aysen valley, is quite as much at home in large sections of the 

 Fuegian steppe and likewise in the Patagonian, as in the district around 

 Lago Nahuel-huapi. 



In the foregoing account of the vegetation of west Patagonia I have 

 occupied myself only with the three plant-communities mentioned. This 

 is not because there are no others represented here, but only because these 

 others are of very secondary importance and in no way comparable to the 

 three dominant plant communities described. 



