Stewart—Botanical Conditions pn the Galapagos Islands . 281 
outside the canyons. 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 Wal- 
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 well 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 Lipoehaeta 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. 
Maeraei, Dodonaea viscosa var. spathulata, Lantana peduncu- 
laris, Maytenus obovata, Telanthera nudicaulis, and Scalesia 
microcephala. Opuntia myriacantha also occurs here but the 
specimens are smaller and not so profusely branched as they were 
lower down. 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. 
