I-O NATURAL HISTORY BULLETIN. 



Jones county, Cedar Rapids and Iowa City, Macbride; Ames, 

 Arthur : Hamilton county, Rolfs; Muscatine, Reppert; Mar- 

 shalltown, Stczvirl; Davenport and Waterloo, Hitchcock; 

 Winnebago and Lee counties, Shiinck. 



3. S. RiGiDA Piirsh. Fl. Am,, 397 (1814). 



S. heterophyUa Pursh. Fl. Am., 396 (1814), not of 

 Schreb. Fl. En., II., 119 (1811). 



Smith, Rev. N. A. Sag. and Loph., 23; Wats, and Coult., 

 Gray's Min., 6th ed., 555; Hitchcock, Ames Fl., 520; x\rthur, 

 Cont. Fl. Iowa, III. 



Edges of lakes or streims; rather common in the eastern 

 and southern portions of the State. Very variable, especially 

 in regard to size and foliage, Julv, August. 



Clinton county, Bugler: Ames, abundant at Cairo Lake, 

 Hitchcock; Muscatine, in Muscatine slough at the upper 

 bridge, five miles below the ciiy, Rcppert; W 3.ter\oo,//itchcock ; 

 Linn county, Shitmk. Specimens collected at Iowa City by 

 Prof. Hitchcock have the submersed foliage closely resembling 

 that of S. teres Wats. 



4. S. GRAMINEA Michx. Fl. N. x\., I., I9O (1803). 



Smith, Rev. N. A. Sag. and Loph., 24; Wats, and Coult., 

 Gray's Man., 6th ed., 555; Arthur, Fl. Iowa, 31; Hitchcock, 

 Ames Fl., 522; Webb, Fl. Neb., 97. 



Southeast portion of the State; ponds and streams. July. 



Ames and Boone, Bessey; Hamilton county, Rolfs; Iowa 

 Q\\.y , Macbride ; Muscatine, Rcppert; Nevada, Fragier ; Carns- 

 forth, Hitchcock, a form approaching S. cristata. 



5. S. CRISTATA Engehn. in Arthur, Cont. Fl. Iowa,V., ( 1882) . 



Proc. Dav. Acad. Sci., IV., 29 (1886). 



S. zari(d)iIis\3.Y. ( ?) grac/iis, S. Watson in Gray's Man., 6th 

 ^^^•^ 555' i" pai"t? not of Engelm. 



Smith, Rev. N. A. Sag. and Loph., 27; Sheldon, Minn. Bot. 

 Studies, Bull. 9. pt. II. 



Monoecious aquatic, rooting in the sand or mud in water a 



