THE VEGETATION OF THE JLAN FERNANDEZ ISLANDS 919 



I^phocolea dh'ergenticiliata Plat^iochasma rupestre 



» sp. Synipliyogyfia citcinnata 



Marchaniia polyiiwrpha 



42. GuJiuera /'ir/A?A?-Sociation. Villagra, below the lower timber-line, forming 

 a fringe along the stream. 51 191 7. Pis. 76:2, 85:2. 



11:3 

 Ciunncra peltata 5 



At the streams in Bahia Cumberland, especially in the settlement, many more 

 species have been found; of these Xastiiriium aqttatiami was introduced on pur- 

 pose. CallitricJie viarginata var. LecJileri (p. 781), indigenous in Chile, Jioicus 

 capillacetis and planif alius, Oldenlaiidia thcsiifolia, all not found before 19 16, and 

 HeleocJiaris maculosa and Polygonum Jiydropiperoides, which were known before, 

 seem to be restricted to the inhabited valley and are supposed to be recent 

 additions to the flora, but may have been brought by visiting birds (e. g. Vanellus 

 cayennensis, Johow 2.238), if not with the traffic. 



TJie Grass-lands. 



In the native grass-land of these islands two species of Stipa dominate, ac- 

 companied by other xerophilous species, and it lies near at hand to refer this 

 type to the steppe formation. The climate is no steppe climate, the vegetation 

 has little to do with a true steppe or prairie, whereas a comparison with the 

 Mediterranean steppe is more acceptable. Similar steppe communities are found 

 in central Chile, where the climate gets its character from the winter-rains and the 

 very dry summer. To judge from the available meteorological observations in 

 Juan Fernandez, the difference in precipitation between summer and winter is 

 less pronounced, but we know from experience that the basal region on the south 

 side of central ^lasatierra, and the entire west section, must receive much less 

 rain than the montane region. In its physiognomy the insular grass-land differs 

 materially from the open country in central Chile in the absence of the xerophilous 

 chaparral shrubs and spring annuals and also in the total lack of Cactaceae. There 

 are numerous annuals it is true, but all of them are aliens. In stony places we 

 also find a few stunted shrubs belonging to species common along the barren 

 ridges in the forested country. 



43. Stipa laevissima-Soc\2Lt\on. Villagra, c. 150 m, 4 — 6,1 1917. On gentle 

 slope; open, sandy-gravelly soil. PI. 100. 



II: 2 Pipiochaetium bicolor I 



Stipa laevissima 4 Polypogon chilensis i 



» neesiana 1-2 Scirpus nodosus i 



Cyperus eragrostis i, rare U 



Halorrhagis ntasatierrana I, rare 



, , Blechnum auncu/atu/n I 



J uncus procerus i, rare 



, , Stergularia conteriinora i 



2 domoeyanus i v- * ./ ./ 



Libertia formosa i 



