638 Part IV. Chapter 5. 
cactus Wislizeni, E. Lecontei (three to six feet high), Opuntia fulgida. At an elevation of 800 feet 
on the plain in which stands Torres, the most conspicuous vegetation is composed of Olneya 
tesota, Cereus (Lemaireocereus) Thurberi, C. (Lophocereus) Schottii, Parkinsonia mierophylla, 
Guaiacum Coulteri, Acacia farnesiana, Randia Thurberi and several malpighiaceous and other woody 
vines which associate themselves with clumps of the trees and shrubs. Maximowiezia sonorae, 
a cucurbitaceous tendril-bearing plant with enormously thickened root and stem base occurs 
beneath some supporting shrub, Westward from Torres, according to CovILLE and MAc DouGAL, 
the line of hills is approached beyond which the country drops toward the coastal plain. 
C. Lower California District. 
1. The Peninsular Territory. 
Lower, or Baja California is a peninsula situated between the Gulf of Cali- 
fornia on the east and the Pacific Ocean on the west. Phytogeographically 
the peninsula may be looked upon as.a distinct district, its flora having 
exceptionally strong affınities with that of Sonora, for out of 732 species, 
500 species are North American. At one time the peninsula may have been 
an island separated from the northern mainland by a wide sheet of water for 
some distance south of the mouth of the Colorado River mud flats and saline 
plains exist, south of which come the volcanic and granitic mountains. 
is district, which has a wet season (June to September), and a dry season, 
is quite thickly covered with large bushes, small trees and an abundance of 
climbing and twining plants. Certain trees increase in size in going south- 
ward, viz., Zyrocarpa Xanti, Aplopappus spinulosus, Aster spinosus, Bebbia 
Juncea, while Atamisquea emarginata ‚ Schoepfia californica and Maytenus 
Phyllanthoides decrease in size. Prosopis juliflora is also abundant. The ex- 
treme southern, or cape region of lower California is characterized by the 
following cacti: Mamillaria Goodridgü, Cereus pecten aboriginum (see Fig. 9 
P- 297), €. Pringlei, C. (Wilcoxia) striatus, C. (Zemaireocereus) gummosus, C. 
Schottii, C. Thurberi, Opuntia prolifera, O. rotundifolia®). 
The spring-flowering plants are Abutilon californiecum, Caesalpinia placida, Acacia 
farnesiana, A. Wrightii, Cereus pecten-aboriginum, C. Pringlei, C. Schottii, C. Thurberi, Diodia 
erassifolia, Pluchea odorata, Buddleia erotonoides, Samolus ebracteatus, Euphorbia Xantii, while 
Perityle crassifolia, F ouquiera spinosa, species of Justieia, Beloperone, Calliandra, Dalea, Tephrosia, 
and Viguiera flower throughout the entire year. The plants here mentioned come into 
flower with the advent of the rainy season: Desmodium, Lopezia, Begonia, Oenothera, 
Mitrocarpum, Stevia, Valeriana, Cyelanthera, Carminatia, Baccharis, Bidens, Verbesina, Hetero- 
spermum, Dysodia, Tagetes, Buchnera, Clevelandia, Mirabilis and Dicliptera2) 
The sandy and gravelly lower coastal slopes near San Felipe Bay furnish suitable condi- 
tions for Lycium Torreyi, Dalea spinosa, Asclepias subulata (in clumps), Argyrothamnia serrata, 
Ibervillea tonella, Croton californicus, Lupinus mexicanus and Frankenia Palmeri. The low alka- 
line pockets reached by the spring tides furnish suitable edaphic surroundings for Spirostachys 
1) BRANDEGEE, T. S.: Cactaceae of the cape Region of Baja California. Zoe II: 18; Field . 
Notes on the Plants of Baja California, Zoe II: 145. 
2) BRANDEGEE, T..S.: The Distribution of the Flora of the Cape Region of Baja California 
Zoe II: 223—231. 
