1 8 PATAGONIAN EXPEDITIONS: BOTANY. 



These treeless slopes are covered with a carpet of mosses, as thick and 

 unbroken as that of the ground in the beech forests just described. On 

 the whole, the same species occur here as in the beech district, with an 

 occasional solitary mound of Sphagnum. Thickets are common and con- 

 sist of almost the same species as those forming the undergrowth in the 

 beech forests, sometimes associated with that splendid fern, Alsophila 

 pruinata, in considerable quantities. There are also less dense thickets 

 made up exclusively or almost exclusively of Lepidothamnusfoncki Phil., 

 a very remarkable shrub belonging to the Coniferce and scarcely reaching 

 the height of one meter. 



The vegetation of these slopes, in many respects, naturally reminds one 

 of the undergrowth in the typical virgin forests, but, at the same time, it 

 has some features in common with the flora of the peat-bogs. For ex- 

 ample, Drosera uniflora, Pinguicula antarctica, Astelia puniila, Gaimardia 

 australis, Oreobolus obtusanguhis, Myrteola nummularia, Blechnum pinna- 

 marina and Schizcea australis are met with in places, all of these belong- 

 ing to the bog vegetation. 



Certain spaces on these slopes are in the course of transformation into 

 tree-bearing ground, Libocedrus tetragona taking possession almost exclu- 

 sively. The beeches are probably far behind-hand, and may be at a dis- 

 advantage because their nuts are less adapted for transportation. At the 

 time of my exploration of the Guaitecas Islands the groves of Libocedrus 

 were about man-high. Judging from their quite considerable density and 

 extension, it will appear that this species of conifer is of far greater impor- 

 tance here than in the southern section. 



3. THE VEGETATION OF THE Rio AYSEN VALLEY. 

 i . The Community of Evergreen Beeches. 



At about 45 23' 30" S. Lat. the Rio Aysen reaches the Pacific, hav- 

 ing cut its way through the whole of the west Patagonian Cordillera. In 

 the district around its mouth in the Firth of Aysen, which penetrates far 

 into the mountain chain, the rainfall is evidently very much less than in 

 the coast district and the islands. This is manifestly proved by the vege- 

 tation, as that compact carpeting of mosses, which is such a characteristic 

 feature of the outer coast district, is entirely wanting here, which cannot 

 otherwise be accounted for than by reason of the rainfall's being less in 

 the Aysen valley than on the coast proper. 



