The Fern Flora of Nebraska*—I 
T. J. FirzPaTrick 
Nebraska lies near the center of the region known as 
the great plains of North America and near the eastern 
side of the semi-arid district. The boundaries are nat- 
ural or nearly so. The Missouri river forms the eastern 
boundary, the northern boundary lies in the valley of 
the Niobrara, the southern in the valley of the Republi- 
can, while the western boundary is in the foothills. The 
range is from the 40th to the 43rd parallel and the west- 
ern border is the 104th meridian. The greatest width 
is 208 miles, the greatest length is 455 miles, the area is 
77,530 square miles, of which 712 square miles are water. 
As to comparative size, Nebraska is much larger than 
all of New England and considerably larger than Eng- 
land and Wales together. The elevation varies from 
785 feet to about 5390 feet. As a whole the state has 
the aspect of a rolling prairie, there being plateaus and 
foothills only in the western portion. The annual rain- 
fall varies from 35 inches along the Missouri river in 
southeastern Nebraska to 14 inches in the semi-arid dis- 
tricts in the western portion. The mean annual tem- 
perature varies from 52° F. in the southeastern corner 
to 45° in the northwestern corner. The recorded evapor- 
ation data give the average annual total amount from 
April to September inclusive, for Lincoln, during an 
eleven year period, as 34.8 inches, and for a three year 
period at North Platte as 41.3 inches. 
The physiographic regions of the state are: (1) river 
valleys, (2) wooded bluffs, (3) prairies, (4) sandhills, 
(5) plateau or foothill region, (6) pine ridge, and (7) bad 
lands. 
*Contribution from the Department of Botany, University of Nebraska, 
No. 30. 
