172 



ELATINACE^E. Waterwort Family. 



Elatine triaiidra, Schk. Long-stemmed Waterwort. 



In mud on margins of ponds and rivers in the Minne- 

 sota valley; in the Missouri valley in Wai worth county, 

 and in White river in the plains region. 



CiSTACE^E. Rock Rose Family. 



Helianthemum niajus, (L.) B. S. P. Hoary Frostweed. 

 On roadsides east of Custer in the Black Hills. 



VIOLACE^. Violet Family. 



Viola pedatiflda, Don. Prairie Violet. 



On prairies in the Minnesota, Sioux and James valleys, 

 and in the Black Hills. 



Viola obliqua, Hill. Meadow Violet. 

 Viola cucullata, Ait. 



Mostly along streams or in the shady places from the 

 Missouri river eastward, and in the Black Hills. 



Viola pedata, L. Bird's-foot Violet. 



On prairies in the Minnesota valley near Bigstone Lake, 

 Viola pa I ust ris, L. Marsh Violet. 



In moist soil near Sylvan Lake in the Black Hills. 



Viola blanda, Willd. Sweet White Violet. 

 In damp ground in the Black Hills. 



Viola Nuttallii, Pursh. Nuttall's Violet. 



On prairies from the James valley westward through- 

 out the state. 



Viola pubescens, Ait. Hairy Yellow Violet. 



In rich woods in Union county in the Sioux valley, 

 and in the Black Hills. Most of the specimens referred 

 to this species belong to the next. 



Viola scabriuscula, (T. & G.) Schwein. Smoothish Yel- 

 low Violet. 

 Viola pubescens scabriuscula, T. & G. 



