162 



teristic of the Hudsonia association, and occasional upon blowout 

 deposits and in black oak woods. 



Lechea sp. In the black oak association in the Winnebago and 

 Oquawka areas. 



Violaccae 



Viola pcdaia L. Hanover, Oquawka, and Winnebago areas, most 

 abundant in the bunch-grass prairie and in the black oak woods, oc- 

 casional in the Panicnni pseudopubcscens association and on blowout 

 deposits. 



Viola lanceolata L. Dixon area, in the Polytrichum association; 

 Kankakee area, in the wet meadows. 



Cactaceae 



Opnniia RaftJicsqttii Engelm. Hanover, Oquawka, and Havana 

 areas, usually very abundant in the bunch-grass and the open parts 

 of the black oak forest. 



Opuntia fragilis (Nutt.) Haw. Hanover area, in the bunch-grass 

 and Pajiicuin pseiidopiibcscois associations. 



Mclastonmccae 



Rhcxia virginica L. Dixon area, in the Polytrichum and Sol- 

 idago associations; Amboy area, in the wet meadows. 



Onagyaccae 



Liidzngia alternifoUa L. Havana area, in the Salix association. 



Ludvigia palnstris (L.) Ell. Dixon and Havana areas, in the 

 swamp association, and persistent as a relic in the Solidago and 

 Polytrichum associations. 



Oenothera biennis L. In the bur oak association in the Winne- 

 bago area, and in the mixed forest in the Havana area. 



Oenothera rhombipctala Nutt. One of the most common inter- 

 stitials, occurring in all seven areas in a wide variety of associations, 

 but most abundant in the bunch-grass and in the Paniciini pseudopu- 

 bescens association. 



Circaea hitctiana L. In the bur oak forest in the Winnebago 

 area. 



Umbelliferae 



Sanicula canadensis L. Winnebago and Havana areas, in the 

 bur oak and mixed forest associations. 



