THE WHITE WATERULY OF IOWA 623 



known this to fail in unquestionally authentic fresh material. 

 hi my limited experience, the time of opening of the flowers 

 has been highly characteristic. The large seeds with relatively 

 small arils are easily recognized in .V. tuberosa. Bu1 critical 



study of much material is necessary in ascertain to what extent 

 these features are constant and diagnostic. 



In the Gray Herbarium of Harvard University and in the 

 private collection of Mr. J. R. Churchill T have examined ma- 

 terial of these species, variously labelled as A', odorata, A. tuber- 

 osa or A', reniformis, from Iowa (Wahonsie Slough, Fremont 

 county, coll. Fitzpatrick, No. -4426), Wisconsin. Minnesota. Mis- 

 souri and Illinois. Of all of these only one (coll. E. E. Sherff. 

 Wolf Lake. Chicago, June 10. 1911) has the form of flower of 

 X. tuberosa. But a note attached to the specimen declares that 

 the flowers are fragrant ! 



It seems highly desirable, therefore, that critical studies 

 should be made of the white waterlilies of all of the Great Lake 

 region, and the Central states. Every detail mentioned in the 

 table given above should be carefully examined into. Only thus 

 can the taxonomic value and the range of these plants be de- 

 termined. At present I do not place entire confidence in any 

 of the published names. I would be glad to serve as a medium 

 of exchange for observations on this subject. 



Department of Botany, 

 Grixxell College. 



