I32 UNIVERSITY OF MISSOURI STUDIES [280 



486. B. nigra (L.) Koch. Black mustard. 



Frequent along roadsides and in waste places, 5100-6000 ft. 

 (Danieis, 747). 

 Europe and Asia, thence to North America. 



487. B. campestris L. Ruta baga. 



Adventitious along the Arapahoe Road, 5300 ft. (Daniels, 

 790). 



Europe, thence universal in cultivation. 



197. ALYSSUM L. Madwort. 



488. A. alyssoides (L.) Gouan. [A. calycinum L.]. Yel- 

 low alyssum. 



Boulder, roadside on University Hill, 5300-5600 ft. (Cock- 

 erell). 



Europe, thence to North America. 



198. K0N1GA Adans. 



489. K. maritima (L.) R. Br. [Alyssum maritimum (L.) 

 Lam.]. Sweet alyssum. 



Spontaneous on the campus of the University of Colorado, 

 Boulder, 5500 ft. (Daniels, 680). 



Europe, thence universal in cultivation. 



199. DRABA L. Whitlow-grass. 



490. D. Coloradensis Rydb. Colorado whitlow-grass. 

 Plains and hillsides near Boulder, 5100-5500 ft. (Rydberg). 

 Colorado. 



491. D. nemorosa L. Wood whitlow-grass. 



At Boulder, University Hill, on rise opposite base of Flagstaff 

 Hill, 5500-6000 ft. (Cockerell). 



Michigan and Ontario to British Columbia; Colorado 

 to Oregon: Europe: Asia. 



492. D. crassifolia Graham. Thick-leaved whitlow-grass. 

 Above timberline. Arapahoe Peak, 11000-13500 ft. (Daniels, 



928). 



Greenland to British Columbia ; Colorado to Utah. 



