I/. The Vegetation of Easter Island, 



By 

 CARL SKOTTSBERG. 



With Plates 28—33. 



In Vol. I, p. 4 — 8, some notes on the geological structure of Easter Island 

 were published; I refer to these notes and to the literature quoted in the same 

 place. Besides, reference should be made to W. Knoche's paper »AIgunas 

 observaciones a la geomorfologia de la Isla de Pascua» (Inst. Centr. Meteor, y 

 Geofis. de Chile, No. 4, p. 150-154; also with German text). Some of his 

 place names are not in correspondance with those on the more recent Chilean 

 map published by me 1. c. Knoche's »Volcan Rana Hana Hana» is = Maunga 

 Terevaka and Rano Aroi, while his »Terevaca» seems to be the same as Cerro 

 Otii on the Chilean map. His »Puukiteke» is Maunga (or Puu) Katiki ; »Puu» 

 is used for »hill» in many Hawaiian names. 



Easter Island scenery is very monotonous (pi. 28, 29). The island is a 

 low, undulating basaltic plateau of practically the same geological structure 

 everywhere and covered by the same kind of vegetation. A considerable 

 number of cones, of many different colours and with a varying petrographic 

 structure, rise above the plains, but their influence on the distribution of the 

 flora is slight if any. Even the highest mountain, Terevaka (530 m) is not 

 sufficiently elevated to call forth any distinct vertical regions. A greater in- 

 terest is attached to the three '>ranos», the comparatively deep craters con- 

 taining a pool of water, but only one of them, Rano Kao, is deep enough 

 (about 200 m) to act as a secluded valley and to offer better conditions for 

 arboreous vegetation. 



The hydrographic features are remarkable. While other volcanic South 

 Sea islands exhibit signs of a very substantial erosion, with deep ravines and 

 narrow ridges, there is not a single valley or ravine in Easter Island with ex- 

 ception of the grooves on the steep crater rims. There is no stream anywhere 

 on the island. Still, the rainfall is considerable, heavier than in Juan Fernandez, 

 where running water is plentiful and erosion very active. This difference be- 

 tween islands of roughly the same structure and with the same type of climate 

 has long attracted the interest of visiting naturalists. Even if we remember that 

 Easter Island is rather low and that, as to its original morphology, it must have 

 been difl"erent fromjuan Fernandez, this cannot explain why not the higher land in the 

 northwest and northeast parts has been cut up into ridges and valleys carry- 



