NOTES ON THE FLORA OF JOHNSON COUNTY, IOWA. 
M. P. SOMES. 
Johnson County lies in the southeastern quarter of Iowa, its eastern 
boundary being about forty-five miles from the Mississippi River reck- 
oning from Davenport and owing to the curvature of the river to the 
westward about eighteen miles from Muscatine. The county has an area 
of about 618 square miles and the elevation ranges from slightly over 
six hundred feet in the southeastern corner to nearly eight hundred 
at Solon. 
The peculiar topographical conditions have been described by Calvin 
(la. Geol. Survey, VII, p. 39) as follows: “Johnson county lies within 
the area of anomalous topographic forms described by McGee (11th Ann. 
Rep. U. S. Geol. Sur.) ; an area in which drift plain interdigitates with 
loess ridge; an area in which rivers go out of their way to avoid low 
lying plains and cut channels longitudinally through ranges of hills that 
rise forty, sixty and eighty feet above broad lowland surfaces that 
apparently might have been traversed with less difficulty, and certainly 
would have afforded a shorter and more direct course, an area in which 
the divides are low and the highlands border the river valleys. The 
county presents an unusual number of topographic phenomena for the 
reason that it is traversed by terminal deposits of the Iowan glaciers, 
deposits forming irregular sinuous ridges that may possibly deserve to 
rank as moraines. Along the northern border of the county there are 
therefore some small lobes of the Iowan drift sheet continuous with the 
gently undulating plains characteristic with regions occupied by de- 
posits of Iowan age in the counties north of Johnson. In the southern 
part of the county all stream valleys are wider and deeper, and the 
relief in general bolder than in the drift plains north of the Iowa mo- 
raine. The greater age of the Kansan deposits has afforded larger op- 
portunities for the agents of erosion to carve and otherwise modify the 
surface. All of the county south of a line drawn from east to west 
through the middle of Scott and Hardin townships may be said to con- 
stitute one area exhibiting the physiographic features of the Kansan 
drift ; but through this area the Iowa River has cut a valley from north 
to south and has developed a broad flood plain with flat alluvium cov- 
