Stewart — Botanical Conditions pn the Galapagos Islands. 281 



outside the canj'^ons. There is no very marked change in the 

 character of the vegetation to an elevation of 2,500 ft., as far as 

 the tufa deposits extend, except that the vegetation thickens up 

 in places and such conspicuous forms as Pisonia floribunda, 

 Tournefortia rufo-sericea, and Zanthoxylum Fagara are added. 

 The two lava flows down the side of the mountain, which cover 

 the tufa deposits, are bare of vegetation except for occasional 

 bushes of Erigeron lancifolius. Euphorbia viminea, and AVal- 

 theria reticulata, while the only plant of tree-like proportions is- 

 Cereus sclerocarpus. In the deep crevices of this lava, however, 

 there is a more abundant vegetation as trees and bushes of Bur- 

 sera graveolens, Cordia lutea, and Zanthoxylum Fagara are to 

 be found, as Avell as a few ferns, among which are Asplenium 

 formosum and Notholaena sulphurea. 



The side of the mountain above an elevation of 2,500 ft. is 

 covered in most places with low bushes, the most common one of 

 which is Lipochaeta laricifolia. This condition continues to 

 within about 150 ft. below the rim of the crater, where there is 

 a narrow zone covered with a dense, and almost an impenetrable 

 growth of Pennisetum exalatum. The rim of the crater is cov- 

 ered with bushes of Cordia galapagensis, Croton Scouleri var. 

 Macraei, Dodonaea viscosa var. spathulata, Lantana peduncu- 

 laris, Maytenus obovata, Telanthera nudicaulis, and Scalesia 

 microcephala. Opuntia myriaeantha also occurs here but the 

 specimens are smaller and not so profusely branched as they were 

 lower do-wn. There are a number of herbaceous plants and 

 ferns among the other vegetation. The vegetation on the floor 

 of the crater appeared to consist of occasional specimens of Cer- 

 eus sclerocarpus and clumps of Dodonaea bushes. 



It seemed impossible to divide this side of the mountain into 

 botanical regions, as was done at the most of the other places vis- 

 ited. There is a great similarity in the vegetation all over this 

 side, and the forms which occur at the top of the mountain are 

 mostly of the same species which occur at or near the base. This 

 rather peculiar condition is probably due to the fact that this 

 side of the island gets very little of the moisture which is brought 

 to the opposite side in the form of fog banks. Mr. R.. H. Beck 

 visited the south side of this mountain, in his search for tortoises^ 

 and reported it to be less sterile than the west side A small lat- 

 eral crater, which occurs on the south side, appeared to be heav- 

 ily covered with vegetation, when seen from the west side of the 

 mountain. 



