PLANT STUDIES IN LYON COUNTY, IOWA. 
D. H. BOOT. 
The subject of this paper is one of a series of ecological studies 
carried on by the author during the last few years, and is a 
study of a part of the region, consisting chiefly of high prairie, 
in the northwestern part of the state, the tract considered cov- 
ering a part of the southwest corner of Lyon county, which is 
the northwesternmost county in Iowa. 
The region for many miles in every direction is dominantly 
prairie, although there , are isolated groves, and fringes of tim- 
ber are found along the streams and in sheltered parts of the 
rougher portions of the territory. The relation of such scat- 
tered groves and timbered tracts to one another, and to their 
prairie surroundings is always of interest, and presents ecologi- 
cal problems as yet only in part solved. 
It is very desirable that detailed local study of the prairie flora 
be carried on in order to determine the many problems regard- 
ing its distribution and development, and the relations existing 
between the prairie plants and those of forested areas. The nu- 
merous environmental factors entering into these problems are 
a source of great interest, and a very inviting field of research. 
This work should be done while undisturbed tracts of prairie 
and forest are still to be found. Such an area was selected for 
consideration in this paper because it is one that shows very 
sharply the transition from forest to prairie; because it is located 
ill the heart of the prairie region ; because it is far removed 
from larger forest areas, and is on the very edge of the great 
plains, there being no forest of any size west of it until one 
comes to the foot hills of the mountains; and because it has 
been but little disturbed by man. 
The locality chosen is in Lyon township, Lyon county, Iowa, 
along the state line. Here the Big Sioux river flows nearly due 
west for several miles, and the hills on the south side of the 
stream rise to a height of 180 feet above the water. In the 
part studied there is a level flood plain about 100 yards in width 
next the river, and then the bluff rises in a timbered slope ex- 
tending south about one-fifth of a mile, to the exposed summit, 
