130 



UNIVERSITY OF MISSOURI STUDIES [2/8 



1901/2. ARMORACIA Gaertn. Horse radish. 



473. A. Armoracia (L.) Cockerell. Nov. comb. [Roripa Armo- 

 racia (L.) A. S. Hitchc. ; Nasturtium Armoracia (L.) 

 Fries.]. Common horse radish. 



Escaped to waysides, Boulder (Daniels). 

 Europe, thence to America. 



191. SISYMBRIUM L. Hedge mustard. 



474. S. officinale (L.) Scop. Common hedge mustard. 

 Common in w^aste places about Boulder, 5100-6000 ft. (Dan- 

 iels, 256). 



Europe and Asia, thence to North America. 



192. SOPHIA Adans. Tansy mustard. 



475. S. leptophylla Rydb. Fine-leaved tansy mustard. 

 Along Boulder Caiion, 6000 ft. (Daniels, 284). 

 Wyoming and Idaho to Colorado. 



476. S. incisa (Engelm.) Greene [Sisymbrium incisum 

 Engelm. ; Descurainia incisa (Engelm.) Britton]. Cut- 

 leaved tansy mustard. 



Boulder Caiion at Falls ; also in Gregory Canon on rocky 

 banks, 6000-9000 ft. (Daniels, 981). 

 Wyoming to New Mexico. 



477. S. intermedia Rydb. Western tansy mustard. 

 Common throughout the lower elevations, 5100-9000 ft. 



(Daniels, 121). 



Michigan to British Columbia; Tennessee to Califor- 

 nia. 



478. S. andrenamm Cockerell. Hoary tansy mustard. 

 Rather frequent in Boulder Caiion, 5500-7000 ft. (Daniels, 



550)- 



Montana to Washington and New Mexico. 



193. ERYSIMUM L. Treacle mustard. 



479. E. asperum (Nutt.) DC. Western wallflower. 

 Mountains between Sunshine and Ward (Rydberg). 

 Saskatchewan to Arkansas and Colorado. 



