RYDBERG: PHYTOGEOGRAPHICAL NOTES 321 
Viola Beckwithiitt : Dugaldia Hoopesiit+ 
Viola Sheltont Senecio filicifoliustttt 
Microsteris micranthat} Polystichum scopulinumtt 
Hydrophyllum alpestrett Selaginella Watsonitt 
Macronema discoideum Selaginella Underwood 
IV. Endemic Rocky Mountain species 
As the endemic element of the montane plants is very large, 
consisting of about 1040 species, or over 53 per cent of the whole 
number, it is hardly practicable to list them all. I shall therefore 
merely give the number of species found in each category and 
mention specifically only a few in each class whose distribution is 
particularly characteristic or of special interest. 
A. ENDEMIC PLANTS COMMON TO THE SOUTHERN AND NORTHERN 
ROCKIES 
Many of the endemic plants are of wide distribution, their 
range extending from Colorado or northern New Mexico to Mon- 
tana or even further north. To this category belong the following 
trees: Pinus scopulorum, Populus angustifolia, Betula fontinalis, 
and six species of Salix (three of these usually mere shrubs). 
Among the shrubs, Sambucus melanocarpa, Ceanothus velulinus, 
and Svida instolonea are the most common and most widely distri- 
buted. The category contains 6 trees, 12 shrubs, and 217 herbs, 
and if to these are added 7 grasses and 6 other herbs belonging to 
the plains and occasionally reaching the Montane Zone, the whole 
number of species is 248. Of these some extend outside of the 
Rocky Mountains, as for instance Svida instolonea, which reaches 
to Manitoba and Kansas, Drymocallis fissa the Black Hills, and 
Scrophularia occidentalis North Dakota and Oklohoma. 
B. PLANTS ENDEMIC TO THE SOUTHERN ROCKIES ONLY 
I. PLANTS FOUND BOTH IN THE MAIN RANGE AND IN THE UINTAH- 
WASATCH REGION 
To this category belong two trees, Picea pungens and Populus 
Wislizenii, together with 13 shrubs and 197 herbs, or in all 212 
species. Of these some are limited to the very southern slope of 
