149 



interstitial between the larger grasses, rarely persisting in the Pani- 

 cmn pseudopubesccns and black oak associations. 



Bouteloua oligostachya (Nutt.) Torr. Hanover area, according 

 to Pepoon. 



Bouteloua curtipendiila (Michx.) Torr. Havana and Oquawka 

 areas, in the bunch-grass association. 



Tridens Haviis (L.) Hitchc. Havana area, chiefly in the bunch- 

 grass, but also in the black oak association and rarely as a relic in 

 the Panicum pseudopiibcscens association. 



Triplasis purpurea (Walt.) Chapm. Oquav^ka area, in the blow- 

 sand association, according to Patterson. 



Bragrostis trichodes (Nutt.) Xash. Havana and Oquawka areas, 

 typically in the bunch -grass but also in the black oak and deposit 

 associations. 



Bragrostis pcctinacca (Michx.) Steud. Hanover, Havana, and 

 Oquawka areas, always in the bunch-grass association. 



Poa compressa L. Sunny places in the black oak association, 

 Havana area. 



Poa pratcnsis L. In a large variety of situations in each area, 

 but chiefly where the land has been pastured or along roadsides. 



Fcstuca octoflora Walt. Hanover, Winnebago, and Oquawka 

 areas, chiefly as an interstitial in the bunch-grass, but also common in 

 the blowsand association. 



Hordcuin pusillum Nutt. A weed along the roadsides in the 

 Oquawka area. 



Blymus virginicus L. Oquawka area, occasional in the bunch- 

 grass association, 



Blymus canadensis L. Hanover and Oquawka areas, in the 

 bunch-grass association and sometimes as a relic in the Panicum 

 pscudopuhescens association. 



Blymus striatus Willd. Oquawka area, a typically mesophytic 

 species of the mixed forest association on the river dune. 



Cyperaceae 



Cyperus rivularis Kunth. Havana area, in the swamp association 

 of an extinct blowout. 



Cyperus Schweinitsn Torr. Hanover, Dixon, Havana, and 

 Oquawka areas, chiefly in the bunch-grass ; common also in the 

 Panicum pseudopubesccns association and rarely in the blowsand. 



Cyperus Uliculmis Vahl. Hanover, Winnebago, Havana, and 

 Oquawka areas, a common interstitial of the bunch-grass, frequent 



