IOWA ACADEMY OF SCIENCES. 167 



TYPHACE.E. 



Typha latifoUa L. Decatur, Wayne, Appanoose, and John- 

 son Cos. Borders of ponds, common. 



Sparganium eurycarpum Englm. Appanoose Co. In shal- 

 low water of Goose lake, common. 



ARACE.E. 



Arlscema triphyllum Torr. Page, Decatur, Appanoose, Shelby, 

 and Johnson Cos. Woods, common. 



A. dracontium Schott. Decatur, Appanoose, Shelby, and 

 Johnson Cos. Damp woods, frequent. 



Acorus calamus L. Appanoose and Johnson Cos. Sloughs, 

 frequent. 



LEMXACE.E. 



Spirodela polyrrhiza Schleid. Decatur, Appanoose and John- 

 son Cos. Ponds, common. 



Lemna trisulca L. Johnson Co. Ponds, common locally. 



ALISMACE.E. 



Alisma plantago L. Decatur, Appanoose, and Johnson Cos. 

 Ponds and flats, common. 



Sagittaria variabilis Englm. Decatur, Appanoose, Shelby, 

 and Johnson Cos Wet sloughs or shallow water, common. 



S. heterophylla Pursh. Appanoose and Johnson Cos. Shal- 

 low water, common. 



S. graminea Mx. Johnson Co. Margins of ponds and shal- 

 low water, frequent. 



NAIDACE^. 



Potamogeton spirillus Tuck. Decatur Co. In a railroad pond, 

 common. Cratty: "This seems to be intermediate between 

 this and P. diversifolius Raf . The submerged fruits are mostly 

 peduncled in your specimens, while they are sessile, or very 

 nearly so in true P. spirillus Tuck. Hitchcock collected the 

 same at Hamburg. ' ' 



P. fluitans Roth. Johnson Co. In ponds, common locally. 



P. paucijlorus Pursh. Henry Co. 



CYPERACE.E. 



Gyperus diandrus Torr. Johnson Co. Sandy soil along 

 river, frequent. 



