152 



Iridaccae 



Sisyrinchiiun sp. Hanover and Oquawka areas, in the bunch- 

 grass association and persisting as a reHc in the Panicnm pseudopu- 

 bescens association. 



OrcJiidaceae 



Cypripediiiin parznfloruin Salisb., var. pubescens (Willd.) Knight. 

 Winnebago area, in the bur oak association. 



Spiranthes cernua (L.) Richard. Dixon area, in the Polytrichum 

 association. 



Salicaceae 



Salix nigra Marsh. Dixon area, in the SalLv association. 



Salix longifolia Muhl. Dixon and Havana areas, in the "Salix 

 association ; Hanover area, in the dune thickets. 



Salix pediceUaris Pursh. Dixon area, in the Polytricliiiui asso- 

 ciation. 



Salix ti'istis Ait. Winnebago and Amboy areas, in the black oak 

 association and as a reHc in the bur oak forests ; Havana area, in 

 the mixed forest association. 



Populus alba L. Ocjuawka area, frequently planted and escaped 

 along roadsides and fence-rows. 



Populus tremuloides Michx. Winnebago, Amboy, and Kankakee 

 areas, in the swamps and meadows between the sand hills, and oc- 

 casional in the bur oak association. 



Popidtis grandidentata Michx. Amboy area, in the bur oak as- 

 sociation, or occasionally as a pioneer in the black oak woods. 



Populus deltoides Marsh. Hanover area, in the dune thickets; 

 Dixon area, in the Salix association ; Oquawka and Havana areas, 

 in blowout thickets. 



Juglandaceae 



Juglans nigra L. Hanover area, in the dune thickets; Oquawka 

 area, in the mixed forest association on the river dune. 



Carya ovata (Mill.) K. Koch. Winnebago area, in the bur oak 

 association. 



Carya cordiformis (Wang.) K. Koch. Hanover area, in the mixed 

 forest; Oquawka and Havana areas, in the l^lack oak association and 

 persisting in the mixed forest. 



