224 UNIVERSITY OF MISSOURI STUDIES [372 



Order 43. CARDUALES. 

 Family no. AMBROSIACEAE. Reich. Ragweed family. 



426. IVA L. Marsh-elder. 



988. I. xanthiifolia (Fresen.) Nutt. Burweed marsh-elder. 

 Common on the plains along streams, and in waste places, 



and following the larger streams several miles into the foot- 

 hills and mountains, 5100-7000 ft. (Daniels, 821). Also in 

 Sunset Canon (Rydberg). 



Michigan and Saskatchewan to Washington ; Nebraska 

 to New Mexico. 



989. I. axillaris Pursh. Small-flowered marsh-elder. 



Railroads and waste places, 5100-6000 ft. (Daniels, 832). 



Saskatchewan to British Columbia ; Oklahoma to Cal- 

 ifornia. 



427. AMBROSIA L. Ragweed. 



990. A. trifida L. Great ragweed. Horse-cane. 

 Common along streams and in low waste places, 5100-6000 



ft. (Daniels, 378). 



Quebec to Assiniboia; Florida to Colorado. 



990a. A. trifida integrifola (Muhl.) T. & G. Entire-leaned 

 ragweed. 

 With the preceding (Daniels, 596). 

 Range of the type? 



991. A. artemisiaefolia L. Common ragweed. 

 Waste places and fields, 5100-6000 ft. (Daniels, 520). 

 Nova Scotia to British Columbia; Florida to Colorado. 



992. A. psilostachya DC. Western ragweed. 



On the plains, especially along railroads, 5100-6000 ft. (Dan- 

 iels, 516). Also at Lyons (Rydberg). 



Michigan to Saskatchewan and Idaho ; Louisiana to 

 California and Mexico. 



428. GAERTNERIA Med. 



993. G. tomentosa (Nutt.) Heller [Franscria discolor Nutt.]. 



