275] FLORA OF BOULDER, COLORADO 12/ 



Family 51. BRASSICACEAE Lindl. Mustard family. 



182. CARD ARIA Desv. 



455. C. Draba (L.) Desv. [Lepidium Draba L.]. Hoary 

 cress. 



Near Boulder, (Rydberg). 



Europe and Asia, thence to the United States. 



183. LEPIDIUM L. Pepper grass. 



456. L. medium Greene. Medium pepper grass. 



Plains and foothills near Boulder, and in Boulder Canon, 

 5000-7000 ft. (Daniels, 123). 



Missouri to Texas and California. 



457. L. divergens Osterh. Divergent pepper grass. 

 Common in creek-sands and along roads and railroads in the 



foothills and mesas, 5400-8000 ft. (Daniels. 32). 

 Colorado. 



184. THLASPI L. Penny grass. 



458. T. arvense L. Field penny grass. 



Local in waste places ; especially abundant along roadsides 

 at the entrance of Boulder Canon. 5100-6000 ft. (Daniels, 163). 

 Europe and Asia, thence to North America. 



459. T. Nuttallii Rydb. Nuttall's penny grass. 



Rocky canons on the north slope of Green Mt, 6000-8100 

 ft. (Daniels, 275). 

 Montana and Colorado to Washington. 



460. T. Coloradense Rydb. Colorado penny grass. 

 Gregory Canon, 6200 ft. (Daniels, 194). Also in wet places 



among rocks, Massif de 1' Arapahoe, 11000-13500 ft. (Ryd- 

 berg). 

 Colorado. 



461. T. purpurascens Rydb. Purplish penny grass. 

 Among rocks on the peaks, Eldora to Baltimore (Rydberg). 

 Colorado to Arizona. 



