160 



and as a relic also in the Polytrichuin association; Amboy area, in 

 muck meadows at the base of the dunes. 



Polygala verticillata L. Hanover, Havana, and Oquawka areas, 

 in the bunch-grass and Panicum pseudopubescens associations. 



Bu'phorbiaccac 



Croton glandulosus L., var. septentrionalis Muell. Arg-. Han- 

 over, Havana, and Oquawka areas, an interstitial in the bunch-grass 

 and Panicum pseudopubescens associations, common in the blowsand 

 association, and occasional on blowout deposits. 



Crotonopsis linearis Michx. Havana area, a common interstitial 

 in the bunch-grass, Panicum pseudopubescens, blowsand, deposit, and 

 black oak associations. 



Euphorbia Geyeri Engelm. Hanover, Dixon, Havana, and 

 Oquawka areas, most abundant in the blowsand association, occa- 

 sional as an interstitial in the bunch-grass and the black oak forest. 



Euphorbia coroUata L. Very abundant in all seven areas, chiefly 

 in the bunch-grass and black oak association, frequent on blowout 

 deposits, occasional in the blowsand association, and rare in the bur 

 oak association. 



Anacardiaceae 



Rhus glabra L. Winnebago and Amboy areas, in the bur oak as- 

 sociation ; Hanover area, in the mixed forest association. 



Rhus Toxicodendron L. Hanover, Oquawka, and Havana areas, 

 in the mixed forest association, in the dune thickets, and occasionally 

 a pioneer in the black oak forest; Winnebago area, in the bur 

 oak and black oak associations. 



Rhus canadensis Marsh., \a.v. illinoetisis (Greene) Fernald. Han- 

 over, Havana, and Oquawka areas, in the bunch-grass, deposit, and 

 black oak associations. 



Celastraceae 



Celastrus scandens L. Havana and Oquawka areas, in the mixed 

 forest; Hanover area, in the dune thickets. 



Aceraceae 



Acer saccharinuni L. Oquawka area, in the mixed forest associa- 

 tion on the river dune. 



Acer Negundo L. Havana area, in the blowout thicket asso- 

 ciation. 



