149 



Brassiea arveiisis, (L.) B. S, P. Wild Mustard. 

 Brassica sinapisti'iini^ Bois. 



A troublesome weed in cultivated fields throughout 

 the state, but more abundant in the eastern part. It is 

 much more abundant and harder to eradicate in the bot- 

 tom lands. 



Sinapsis alba, L. White Mustard. 

 Brassica alba^ Bois. 



A weed in cultivated and waste places throughout the 

 state. 



Roripa siiiiata, (Nutt.) A. S. Hitchcock. Spreading 

 Yellow-cress. 



Occasional in low places from the Missouri valley 

 eastward. 



Korii)a palustris, (L.) Bess. Marsh Water-cress. 

 Nasturtium, pahistris^ DC. 



In low, wet places throughout the state. 



Roripa hispida, (Desv.) Britton. Hispid Yellow-cress. 

 Nasturthini hispidhi^n^ DC. 



Occasional in low places from the Missouri valley 

 eastward. 



Koripa iiastiirtiuin, (L.) Rusby. Water-cress. 

 Nasturtium officinale^ R. Br. 



Naturalized near Hot Springs in the Black Hills. 



Koripa ariuoracia, (L.) A. S. Hitchcock's Horseradish. 

 Nasturtium armoracia^ Fries. 



Sparingly introduced into the Sioux valley. 



Cardainine bulbosa, (Schreb.) B. S. P. Bulbous Cress. 

 Cardamine rhomboida^ DC. 



In shallow water and low meadows in the Minnesota 

 and Sioux valleys. 



Cardamine rotiindifolia, Michx. American Water-cress. 

 In cold, springy bogs in the Minnesota region. 



