THE PLANT GEOGRAPHY OF 

 THE LAKE OKOBOJI REGION 



The present paper is based on observations made in the region 

 of Okoboji and Spirit lakes in northwestern Iowa. The greater 

 part of the work was done by the writer and his assistants during 

 the years since the establishment of the Macbride Lakeside Lab- 

 oratory in 1909, but the earliest part of it dates from the year 

 1894, when, during a very low stage of the water in the lakes, a 

 very satisfactoiy study of the aquatic fiora, flowering and fruit- 

 ing in unusual abundance, was made by the w^riter. During the 

 following years, and previous to the establishment of the labora- 

 tory, repeated visits were made to the region under discussion, 

 the most extended being that of the summer of 1901, when a sum- 

 mer session, with eighteen volunteer students of botany, was held 

 near the station Okoboji, between East and West Okoboji lakes, 

 as a test of the desirability of the region for the location of a 

 permanent biological station. 



It is the purpose of this paper to present to students of the 

 laboratory a general discussion of the flora of the region in its 

 relation to physical environment, as a basis for more extended 

 research in special lines, and also to set before botanists a picture 

 of a region which shows an unusual combination of floral fea- 

 tures. 



PREVIOUS WORK 



The first recorded botanical work was done in this region by 

 the Nicollet expedition in 1839. The report of the expedition ^ 

 includes a crude map of the lake region, in which Okoboji lakes 

 are proportionately small, widely separated, with the west lake 

 extending almost due east and west, and the Okoboji river emp- 

 tying into its western extremity ! 



1 J. X. Nicollet. Report intended to illustrate a Map of the Hydrographic Basin 

 of the Upper Mississippi River. (Senate) 26th Congress, 2d Session. Published in 

 1843. 



3 



