153 



Betulaccae 



Corylus aincricana Walt. Hanover area, on the perched dunes ; 

 Winnebago and Amboy areas, common in the bur oak association and 

 occasional as a pioneer in the black oak forest. 



Betula nigra L. Hanover and Oquawka areas, in the mixed for- 

 est association near the river. 



Betula alba L., var. papyrifera (jNIarsh.) Spach. Hanover area, 

 on the perched dunes. 



Pagaceae 



Quercus alba L. Winnebago area, in the bur oak association. 



Qnercns macrocarpa Michx. Winnebago and Amboy areas, the 

 characteristic species of the bur oak association, 



Quercus rubra L. Oquawka area, in the mixed forest association. 



Quercus veliitina Lam. Hanover, Winnebago, Amboy, Kanka- 

 kee, Havana, and Ocjuawka areas, the characteristic species of the 

 black oak association, persisting commonly as a relic in the mixed 

 forest association and less commonly in the bur oak forest; common 

 on the perched dunes in the Hanover area. 



Quercus inarilandica Muench. Havana and Oquawka areas, 

 abundant in the black oak association, and persisting in the mixed 

 forest. 



Urticaceae 



Ulnius aniericaua L. Hanover and Ocjuawka areas, in the mixed 

 forest association and in the dune thickets. 



Celtis occiclentalis L. Hanover and Havana areas, in the mixed 

 forest association, and in the l;)lowout and dune thickets. 



Morus rubra L. Havana area, in the mixed forest association. 



Boehuicria cylindrica (L.) Sw. Havana area, in the Salix as- 

 sociation. 



Parietaria pennsylvanica Muhl. Oquawka area, in the mixed for- 

 est association. 



Santaloccae 



Comandra umbellata (L.) Nutt. Hanover, Winnebago, Amboy, 

 Oquawka, and Hanover areas, in the black oak association, or oc- 

 casionally along roadsides. 



Polygonaceae 



Runiex altissiinns Wood. Hanover area, in the black oak asso- 

 ciation. 



