GRASSES OF IOWA. 



381 



this by about one-fourth of a degree. On the 42c! parallel of latitude 

 the distance across the state is 380 miles. On the east the state is bounded 

 by the Mississippi, on the west by the Missouri, and in the northwestern 

 part of the state the counties of Lyon, Sioux, Plymouth and a small por- 

 tion of Sioux, by the Hig Sioux. Owing to the general trend of the 

 streams, the northern and southern boundaries are not separated by 

 rivers from the adjoining states, except a small portion of Lee county, 

 where the Des Moines forms the boundary. On the whole, the state is 

 what may be called a typical prairie state, consisting of undulating hills 

 traversed by numerous small streams which during the greater part of 

 the year carry but little water. Toward the Mississippi, especially in 

 the northeastern part, the country is decidedly rough, especially in Clay- 

 ton, Allamakee and Winneshiek counties. 



Fig. 259. Mar9h in northwestern Iowa, Spirit Lake. Glyceria nervata, Erigeron 

 annuus, Juncus. (L. H. Pammel. Photo. ) 



DRAINAGE. 



About three-fourths of the state is drained toward the Mississippi, 

 receiving its drainage as far back as 95° longitude from the eastern part 



