SCROPHULARIACEAE OF THE CENTRAL ROCKY 
MOUNTAIN STATES. 
By Francis W. PENNELL. 
INTRODUCTION. 
The purpose of a series of papers, of which this is the first, is to 
present in summarized form our knowledge of the plants of the 
family Scrophulariaceae growing within the states of Wyoming, 
Colorado, and Utah, and in Idaho west to the 113th meridian. 
Within this area it is planned to consider all species, and to give for 
each its taxonomic history, its flowering season, and its distri- 
bution. 
Eastward from these states occur the Black Hills, with a flora 
akin to that of the foothills of the Rocky Mountains, and southward 
from them a great expanse of high plains in all respects identical 
with the high plains of eastern Colorado. To include the former 
and a large portion of the latter, the area of this study has been 
extended eastward to the 100th meridian. From this additional 
territory—western Kansas, western Nebraska, and southwestern 
South Dakota—comparatively few specimens have been seen, and 
consequently the specimens here cited do not indicate with the same 
degree of completeness the distribution of the species. However, 
eastward the species of this family are few and mostly long known. 
Within the large area of this study, an area except for slight 
irregularities on its northwestern boundaries rectangular in outline, 
occurs a considerable diversity of natural environment, but a much 
greater diversity of flora. The lower and vastly the larger portion 
consists of a flat or rolling tableland, sloping upward from our 
eastern frontier, the Platte River below North Platte at about 750 
meters altitude, to about 2,130 meters altitude on the continental 
divide in southern Wyoming. Northward, westward, and south- 
ward occur various broad valleys and relative depressions. The 
most important are the valleys of the Powder, Tongue, and Bighorn 
rivers in northern Wyoming; of the Snake River in southeastern 
Idaho; the broad basin of the Great Salt Lake, itself about 1,300 
meters in altitude, and the deserts westward; the valley of the 
Virgin River of southwestern Utah, at St. George but 840 meters 
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