Vol. I] STEWART— BOTANY OF THE GALAPAGOS ISLANDS 207 



While it is difficult to give a list of plants which are strictly 

 characteristic of this region, the following includes those spe- 

 cies which are most common. Those which are followed by 

 an asterisk in this and the following lists are, so far as is 

 known, characteristic of the region to which they are referred. 



Acacia macracantha* Desmanthus depressus 



Aristida divulsa* Discaria paucMora* 



subspicata* Erythrina velutina* 



Borreria ericaefolia* Euphorbia amplexicaulis* 

 Bursera graveolens articulata* 



Castela galapageia viminea 



Cenchrus platyacanthus* Gossypium barbadense 



Cereus galapagensis* Lantana peduncularis 



nesioticus* Maytenus obovata 



sclerocarpus* Mentzelia aspera 



Clerodendron molle Opuntia galapageia* 

 Coldenia Darzvini* myriacantha* 



fusca* Parkinsonia aculeata* 



Cordia galapagensis Piscidia erythrina 



Hookeriana Prosopis dulcis 



lutea Scalesia atractyloides* 



Croton Scouleri* Telanthera echinocephala 



var. brevifolius nudicaulis 



var. Macraei* Waltheria reticulata 



Transition Region 



As the name would indicate, the vegetation in this region 

 is transitional in character, being made up of a mixture of 

 xerophytic plants from the dry region below and the more 

 hardy of the mesophytic plants from the moist region above. 

 There is usually a great thickening of the vegetation in this 

 region, and a considerable number of the evergreen species 

 appear, so that the landscape has a mottled appearance when 

 seen from a distance. In fact the deciduous character of the 

 vegetation in the dry regions, the evergreen character in the 

 moist regions, and the mixture of the two in the transition 

 regions, are the principal causes of the well marked appearance 

 of zonation on many of the islands. 



The trees in this region are taller, as a rule, and closer • 

 together than they are in the dry region, while underneath 

 the trees the bushes and undergrowth are larger and thicker 

 on the ground. A few species of epiphytic plants are found, 



