208 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4rH Ser. 
among which fruticose lichens are most abundant, often occur- 
ing in such large quantities as to give a distinct color to the 
vegetation. A few of the more xerophytic species of ferns, 
as well as a number of herbaceous perennial plants, occur. 
The annual herbaceous forms are rather in the minority as 
compared with the perennials. The following list includes the 
plants which are most common in this region. 
Adiantum concinnum Lantana peduncularis 
Bursera graveolens Lipochaeta laricifolia 
Castela galapageia Maytenus obovata 
Ceropteris tartarea Pisonia floribunda 
Chiococca alba Polypodium lepidopteris 
Cissampelos Pareira pectinatum 
Clerodendron molle squamatum 
Cordia galapagensis Psidium galapageium 
Hookeriana Psychotria rufipes 
lutea Scalesia pedunculata 
Croton Scouleri var. brevifolius Telanthera echinocephala 
Doryopteris pedata Tillandsia insularis 
Erigeron tenuifolius Tournefortia rufo-sericea 
Euphorbia viminea Trachypteris pinnata 
Gossypium barbadense Waltheria reticulata 
Ionopsis utricularioides Zanthoxylum Fagara 
Moist Region 
The vegetation of the moist region is of a decidedly meso- 
phytic character, all the xerophytic species which persist in the 
transition region having disappeared, except in a few rare 
instances. In these cases there may be an occasional straggler 
from below, or conditions of soil or exposure are such that 
mesophytic plants will not grow. In general this region is 
characterized by the presence of large forests, made up for the 
most part of trees of Psidium galapageium, Pisonia floribunda, 
and Scalesia pedunculata, which it seems well to call the 
“Scalesia forests.” The undergrowth is often dense in these 
forests, and is made up mostly of larger species than are found 
in the two lower regions. Epiphytic ferns and orchids, as well 
as several species of leafy hepatics, grow abundantly. Lianes 
also abound, although belonging largely to a single species. 
The mesophytic species of ferns are very common, and often 
form brakes of considerable size. In general, the vegetation 
