RYDBERG: PHYTOGEOGRAPHICAL NOTES 325 
Montane plants in the restricted sense, i. e. plants which attain 
their best development within this zone. Of the rest, many reach 
their best development in the Subalpine Zone above, and many 
others in the Submontane Zone below. A few alpine plants are 
sometimes found as low as the Montane Zone and several species 
from the Great Plains or from the Sonoran Zone are occasion- 
ally found as high up. 
Of the plants found in the Montane Zone, 245, or less than 
I3 per cent, are transcontinental, i. e. they are found both in the 
East and on the Pacific Slope, as well as in the Rockies; 176 of 
these, or 9 per cent of the total flora, are common to the Northern 
and Southern Rockies, another 1 per cent extend as far south as 
Wyoming, and 1 per cent are limited to the Canadian Rockies. 
Besides the transcontinental plants, there are 84 species which 
are common to the East and the Rockies but have not reached the 
Pacific Slope. If to these are added a score of western plants 
which have emigrated eastward as far as the Great Lakes and 
Hudson Bay, some of them even to the Gaspé Peninsula, Quebec, 
there are in all about 350 species, or nearly 1814 per cent of the 
flora, which are common to the East and to the Rockies. The 
larger portion of these, 250 species or over 13 per cent, are found 
in both the Northern and Southern Rockies, and 100, or more than 
5 per cent, in the Northern only. None of the Montane plants 
are common to the East and the Southern Rockies only. 
The number of species common to the Rockies and the Pacific 
Mountains is much larger: if the transcontinental species are 
excluded, about 565, or nearly 30 per cent; or, if these are included 
nearly 43 per cent of all the plants found within the Montane Zone 
of the Rockies. Nearly 450 of the plants common to the Rockies 
and the Pacific Mountains (the transcontinental ones included), 
or nearly 24 per cent of the whole number are found in both the 
Northern and Southern Rockies; 350, or about 18 per cent, are 
found in the Northern Rockies but not in the Southern, and 
Not quite 2 per cent occur in the Southern but not in the Northern 
Rockies. Of the species common to the Rockies and the Pacific 
Mountains (the transcontinental ones not included), about 300, 
or nearly 16 per cent, are found both in the Cascades and the 
Sierra Nevada; about 225, or nearly 12 per cent, are found in the 
