310 THE AMERICAN NATURALIST. [VoL XXXIII. 
North America, but are restricted to the Pacific side of the 
continent. The genus Fritillaria is represented by a number 
of showy species, one of which extends as far south as San 
Diego ; another striking instance is the western skunk cabbage, 
Lysichiton, a monotypic plant common to the north Pacific 
coasts of Asia and America. 
In the valleys of the central part of the state and throughout 
the southern regions the plants are very different from those 
of the north, and have very little in common with the flora of 
the eastern states. Mexico and western South America are 
the regions which are most nearly allied in their flora to this 
southern district. Most of the characteristic genera of this 
region are either entirely absent from the Atlantic states, or 
else represented by very few species. Much of this area is 
excessively dry, and such plants as the cacti, agaves, yuccas, 
and other desert types give a very marked character to most 
of this region. 
The central part of the state, especially the region about the 
bay of San Francisco, is a meeting-ground for the northern and 
southern floras. In the valleys the flora is largely composed of 
the southern elements. Such genera as Lupinus, Eschscholtzia, 
Nemophila, Orthocarpus, Brodizea, Calochortus, Calandrinia, 
and other common and showy flowers of the open valleys and 
foothills, are represented by species either identical with the 
southern ones or closely allied to them. The flowers of the 
higher mountains, however, especially those of the moist for- 
ests of the outer coast ranges, are largely of northern origin, 
and these often follow the sheltered canyons down to the level 
of the valleys, where they mingle with the valley flora. 
Probably no feature of our Pacific flora strikes the eastern 
botanist so forcibly as the preponderance of coniferous trees. 
From Sitka to San Diego, it is Conifers which give the peculiar 
stamp to the forests, whether at the timber line on the highest 
peaks, or battling with the ocean winds along the coast. It is 
true that in the valleys and on the lower hills groves of oaks, 
without accompanying Conifers, are met with; these can hardly 
be said to form forests, and wherever the moisture is sufficient 
to support a true forest growth, it is the Conifers which are the 
