Lower California District. 639 
foxia arenaria, Rhachidospermum mexicanum, Hofmeisteria fasciculata and Stegnosperma halimi- 
folia. The lagoons near La Paz are characterized by sub-tropie maritime brackish-water plants, 
such as Conocarpus erectus, Avicennia nitida, Ipomoea acetosaefolia, Laguneularia recemosa, Scae- 
vola Plumieri, Samolus ebracteatus and Centunculus minimus. At an elevation of 3,000 feet 
(1000 m), southwestward of San Felipe Bay, the granite slopes support a sparse vegetation of 
Bursera microphylla, Asclepias albicans, Eriogonum inflatum and species of Mammillaria, Ephedra, 
Yucca, Agave and Opuntia. Two palms are abundant along streams on he eastern slopes of 
the higher mountains, viz., Washingtonia sonorae and Erythea arctuata. 
The most interesting feature of the district however, consists in the great 
number of mud volcanoes covering an area of about two square miles on the 
southern shore of Volcano Lake. These are in an active state and the soil 
near them is highly charged with saline matter and sulphur. Sesuvium por- 
tulacastrum is abundant in places, but extensive areas here are absolutely 
devoid of vegetation. 
San Pedro Martin Mountain, situated about ı25 miles southeast of 
San Diego, is an extensive and elevated plateau, having an elevation of 7—8000 
feet and traversed by numerous rocky ridges 2000 or 3000 thousand feet 
‚higher. Northern plants, favored by the climate, which is cold in winter 
and with a rainfall greater than in the lowlands reach the middle portion of 
Lower California. Trees of good size are found almost over the whole plateau. 
Pinus ponderosa var. Feffreyi forma peninsularis is the most common, but on 
the ridges a few sugar pines (Pinus Lambertiana) and along streams ‘some 
cedars (Zibocedrus decurrens) keep them company. In a few localities Populus 
fremuloides, Cupressus guadalupensis, Abies concolor can be found, but they 
are not common and at lower elevations Pinus Parryana is almost the only 
tree. Oaks, (O. agrifolia, Q. Wislizeni, Q. chrysolepts, O. grisea, O. dumosa), 
are plentiful, Garrya, Cranothus cordulatus and Rhamnus calıifornıca are common, 
with plants of genera which belong to a temperate climate and are found 
only on the high mountains °). 
2. The Insular Territories. 
"The flora of the islands of the coast of lower California is of considerable 
interest. San Pedro Martin Island has three endemic species: Hofmeisteria 
laphamioides, Pelucha trifida and Perityle Emoryi. Raza Island is excep- 
tionally rocky, except a few low areas. Upon this island grow Opuntia ipenigee 
O. echinocarpa, Sesuvium portulacastrum, Salicornia ambigua, Atrıplex dılatata 
and A. insularis. The fora of Carmen Island, one of the largest, is almost 
identic with that of the peninsula and may be neglected here‘). The plants 
1) MacDoucar, D. T.: Delta and desert Vegetation. Botanical Gazette XXXVIH: 44—63 
July 1904. 
2) BRANDEGEE, T. S.: Southern Extension of Cali 
3) VAsev, G. and Rose, J. N.: See Bibl. p. 8 
fornia Flora. Zo& IV: 199210. 
GREENE, E. L.: See Bibl. p. 83. 
’ 
