Affinities: Western North America. 323 
clusively North American, as accurately as possible for those confined to western North America, 
a somewhat laxer rule bas been observed for the two smaller subdivisions. These are merely 
politic, and have little Tre significance, and the limits of many of their plants as 
yet are not known accurately. For these reasons they are included in the number aceredited to 
California and to ame California, some plants which, while properly belonging to them, extend 
a little beyond their boundaries. This table brings out the distinetively west American character 
the flora. 
Two-thirds of the genera, it is 
true extend their range beyond 
North America; but of the remai- 
ning one-third, only 14 per cent 
are found east of the Rocky Moun- 
tains, while 86 per cent of this 
third are confined to the territory 
west of them, and of these about 
one half are restricted to Cali- 
fornia. This local differentiation 
is much more pronounced in the 
species than in the genera. Less 
than one-eighth of the indigenous 
species extend beyond North 
America. Among the North 
American species less than 8 per 
cent pass beyond the Rocky, 
Mountains; of the species occur- 
ring west of the range nearly 
60 per cent are exclusively Cali- 
fornian; of the Californian species 
over one-half are confined to the 
southern counties of the state. In 
the Pteridophyta, the species are 
about equally divided between 
those of North America and those Fig. 14. Darlingtonia californica Torr. The Cali- 
ä us i fornia ng ar native to boggy places at middle 
of wider distribution, the develop- eyatons in the Sierra Nevada of northern Cali- 
ment of the Gymnospermae iS gornia to sonthern Orlgde, flowering from May to July. 
entirelyNorth American;theMono- After Die Natürlichen Pflanzenfamilien III 2, p. 246. 
cotyledoneae are 80 per centNorth 
American, the Choripetalae 88 per cent, and the Gamopetalae g2 per cent. 
The coast islands of California show a few peculiarities worthy of mention. 
According to LE CONTE'), out of 296 species of plants collected on the island 
of Santa Cruz, no less than 48 are entirely peculiar to the coast islands, and 
28 peculiar to Santa Cruz itself. Of the remaining 248 species, nearly all are 
1) Le Conte, Josepn: The Flora of the coast Islands of California in relation to recent 
Changes of physical Geography. Bulletin California Academy of Sciences, 8. er 19, 1887. 
