xliv 
BOTAOT. 
Atlantic species increases to one-fourth and that of the Pacific diminishes to 
three-fifths. 
Looking at the Basin flora as a whole it appears to a considerable 
degree a distinct one. Though the position of the territory would rather 
indicate as probable an intermingling of the surrounding floras, of the Cali- 
fomian with that of the Rocky Mountains, aud of the extreme northern, 
descending along the mountain ranges, with that of the deserts of Arizona 
spreading northward in the valleys — as indeed is largely the case — yet it has 
a marked character of its own. This consists partly in the absence of many 
of the peculiarities of the surrounding floras. A very large portion of Pacific 
species, not only arborescent but shrubby and herbaceous, stop abruptly upon 
the eastern slope of the Sierras and do not reappear eastward. For this reason 
the California district should be considered as limited on the east by that 
range, tlie whole southeastern portion of the State and a smaller section in the 
northeastern part belonging geographically and botanically to the Colorado 
Desert and to the Basin respectively. A Uke line of demarcation is shown 
on the eastern side at the base of the Wahsatch by the immediate accession 
of new orders and species characteristic of the eastern flora. Again many of 
the forms prevalent farther south are wanting or appear only on the borders 
of Nevada and Utah,. as most of the Cactaceoe and of the Daleas and other 
large leguminous genera and even suborders, characteristic Rutaceous and 
Zygophyllaceous species, the Cucurhitacece and Loranthacece, Salvia, and the 
larger portion of the Solanacece, Euphorhiacece and Byctaginacece. The 
mingling with northern species is necessarily more intimate, yet with a more 
exact knowledge of the habitats of "Oregon" species a well marked limit 
of the Basin flora could probaldy also be drawn in that direction. But aside 
from these deticicncies, the general preponderence of senecioid composites, 
of which the Artemisia tndentata may be considered the prevailing represen- 
tative, and the so marked number of chenopodiaceous genera and species, 
many of which do not extend greatly beyond the limits of the Basin, make the 
flora a singular one and warrant designating the district as one of Artemisias 
and Chenopods. The alnindance of species of Astragalus, Eriogonum and 
the allied genera, CEnothera, Pentstemon, and Phacelia, is also in a more or 
less degree distinctive. 
The following table shows the distribution of the genera and species 
arranged by orders: 
