THE VEGETATION OF EASTER ISLAND 



495 



PaspaliDii scrobiculatnin to Spoiobolus and that this is the reasom why the 

 former is less common. 



Uniform as are tlie conditions all over the island there remain, however, 

 a number of habitats where the meadow gives way to other associations. Such 

 places are the sea shore, the rock faces in inland stations, the moisture-contain- 

 ing crevices in the hill-sides and, above all, the crater lakes. 



The plant associations. 



The notes were taken of squares approximately lOXlO m. The stratifi- 

 cation is indicated as follows: shrub stratum (S) 1.8—6 m; field strata, F3 0.6—1.8 

 ni, F2 0.2 — 0.6 m; F^ less than 0.2 m, but above the ground cover (G) with 

 its matted cryptogams and appressed phanerogams. The relative dominance 

 is indicated by the figures 5 to i. Species considered to be indigenous are 

 italicized in the plant lists. 



ASSOCIATION.S OF THE SEA SHORE 



As a rule, the coast is rocky, and the basalt cover terminates in a more 

 or less high escarpment, beaten by the surf or protected by heaps of rock 

 debris. A sandy shore is found only in few places and best developed in 

 Hanga Ho Orno (La Perouse Bay), but no special psammophilous flora was 

 noted. Along the rocky shore the grassland comes down over the clifis and 

 forms broken patches in nooks and corners. 



Hanga Ho Orno, June ij, igij. Stony and rocky shore; scattered co- 

 lonies. 



F2 Erigeron linifolius, 2 among smaller stones on fine- 



Verbena litoralis, 2 grained material 



Bidens pilosa, i Porttdaca oleracea, i 



Fi CJienopodhi7n avibigiiiun, i G Euphorbia serpens, 3 

 Ipomaea pes caprae, i, very rare, 



In a small cave: Fj Asplenium obUisatuiii, i 

 Coronopus didymus, i 

 Oxalis corniculata, i. 



The wide-spread tropical Pes-caprae-Kss. was not observed, but may occur 

 in places not visited by us. 



Lichen associations on the rocks. 



Close to the water's edge: Pannelia conspevsa var. lusitana (small speci- 

 mens, yellowish grey), Pyxinc enteroxantha (yellowish), Caloplaca rubina (minute 

 red dots). 



Some distance above the water: Buellia Glazmiana (straw-coloured, black 



