Stewart — Botanical Conditions ,on the (Halapogos Islands. 325 



condition is local, however, as the most of the soil on the lower 

 parts is composed of disintegrated lava with small boulders and 

 bits of lava intermixed. There are also lava ridges in this vicin- 

 ity without soil. 



Tlie slope is very gradual to 700 ft. and in places the country 

 is slightly terraced. Above this elevation the ascent is quite 

 steep to 1,000 ft. beyond which there is a broad valley, three or 

 four miles wide, extending in to the base of the craters on the 

 west side of the island. There is a heavier growth of vegetation 

 here than on the north side of the island, probably due largely 

 to the fact that there is more soil. 



About the only vegetation on the beach, where we landed, was 

 a sparse growth of Sporobolus virginicus, but back of the beach 

 around the base and on the sides of the cliffs there were bushes 

 of Cryptoearpus pyriformis, Discaria pauciflora, and Maytenus 

 obovata. Grassy areas occur back of the shore, where the soil is 

 composed of ashes, which at the time of our visit Avere covered 

 with a heavy growtli of Aristida subspicata. There is probably 

 quite a growth of annual plants in addition to the above, during 

 the rainy season, as the remains of quite a number of these were 

 found. Patches of bushes occur in the grassy areas which are 

 made up of such species as Acacia macracantha, Clerodendron 

 molle, Cordia lutea, Croton Scouleri var. brevifolius, Gossypium 

 barbadense, and Waltheria reticulata forma intermedia. Low 

 trees of Bursera graveolens and Piscidia Erythrina occur among 

 the bushes. A few specimens of Opuntia grow in the vicinity of 

 the shore but whether or not these are 0. myriacantha or the un- 

 described species from the north side of the island, was not de- 

 termined, as no specimens were collected. They are more abun- 

 dant farther inland. 



The character of the vegetation changes but little to an eleva- 

 tion of 3-00 ft. except that the grassy areas soon stop and the 

 country is covered with Bursera forests veiy similar to those on 

 the lower parts of other islands. Trees of Erythrina velutina 

 also occur here in considerable number. Cissampelos Pareira 

 appears first at about 300 ft. elevation, but it becomes more 

 abundant liigher up where it often covers trees and bushes. A 

 few of the more xerophytic species of ferns appear around an ele- 

 vation of 400 ft. We experienced much difficulty with the 

 thickets of Furcraea cubensis at an ek.ation of 450 ft. and 

 above, as they often cover areas of several acres in extent in this 



