Ustilago tritici (Pers.) Jens., on wheat. 

 Ustilago zeae (Beckm.) Ung., on corn. 

 Arthur also reported the following: 



Puccinia coronata Corda, on Avena sativa. 

 Ustilago segetum (Bull.) Ditt., on Avena sativa. 

 Peronospora effusa (Grev.) Eabh., on Chenopodium album. 



Nepeta cataria is exceedingly abundant in some of the pastured groves. 



In the preceding lists the nomenclature of Gray's Manual, 7th ed., is em- 

 ployed in the main for vascular plants; Saccardo's Sylloge Pungorum for 

 fungi ; and Macbride 's North American Slimemoulds for Myxomycetes. The 

 discussion of sjmonymy, etc., will be taken up later, in the annotated list to 

 be published. 



1. The lake region furnishes striking and added evidence of 

 the influence of atmospheric factors on the formation of prairies, 

 and emphasizes the conclusion that exposure to dry winds and 

 sun is the chief cause, even the proximity to larger lakes being 

 insufficient to overcome these factors excepting where topography 

 permits the accumulation of vapors. 



2. The variation of the soils in which prairie plants grow 

 from fine prairie loam to sand and gravel again demonstrates 

 that fineness of soil is not the determining factor in prairie 

 formation. 



3. The deep woods flora of the region represents an atten- 

 uation of the easterly and southeasterly forest flora. 



4. The borders of the prairie groves, and the more open 

 groves, present a combination of ecological and floral conditions 

 which clearly mark them as transition areas. 



5. The hydrophytic flora is unusually rich and varied for this 

 state, and offers the best opportunity within its limits for the 

 study of deeper water forms. 



INTRODUCED WEEDS OP THE WOODS 



Arctium minus Bernh. 



Cirsium lanceolatum (L.) Hill. 



Cannabis sativa L. 



Chenopodium murale L. 



Capsella bursa-pastoris (L.) Medic. 



Dracocephalum parviflorum Nutt. 



Euphorbia cyparissias L. 



Leonurus cardiaca L. 



Linaria vulgaris Hill. 



Lychnis alba Mill. 



Melilotus alba Desv. 

 Melilotus officinale (L.) Lam. 

 Nepeta cataria L. 

 Nepeta hederacea (L.) Trev. 

 Pastinaca sativa L. 

 Solanum nigrum L. 

 Sonchus asper (L.) Hill. 

 Sisymbrium officinale (L.) Scop. 

 Taraxacum officinale Web. 

 Trifolium procumbens L. 



CONCLUSIONS 



66 



