240 GEOLOGICAL SURVEY OF CANADA. 



284. IVA, Linn. (MARSH ELDER.) 



(1117.) I. axillaris, Pursh. Hook. Fl. I., 309. 



On dry or wet saline soil. Along the Saskatchewan from Carlton to 

 Edmonton. (Drummond.) Very common on. the margin of saline 

 lakes and ponds throughout the prairie region. (Macoun.) Short 

 Creek, Souris 'River, 49th parallel, and abundant westward on hard 

 baked clay. (Dawson.) 



(1118.) I. xanthiifolia, Nutt. 



Cydachxna xanthiifolia, Fres. Torr. & Gray, Fl. II., 286. 

 In alluvial soil along rivers and small streams. Reed Lake, west of 

 Old Wives' Lakes ; at Setter's Farm, Cypress Hills ; and on the slope 

 of the high bank between Fort Edmonton and the river. (Macoun.) 

 Swift Current Creek, C. P. R. Crossing ; and at Fort Qu'Appelle close 

 to the Hudson Bay Co.'s store. (./. M. Macoun C. P. R. Coll.} 



285. Ambrosia, Tourn. (RAG-WEED.) 



(1119.) A. triflda, Linn. 



Low grounds along streams. Common in the vicinity of Montreal. 

 (Holmes & Ami.) In a boggy field near St. Louis Dam, Ottawa. 

 (Macoun & Fletcher.) Cayuga and Maiden, Ont. (Maclagan.) Along 

 the northern slope of the Cypress Hills. (Macoun.) Vicinity of 

 Winnipeg. (Bourgeon.) 



Var. integrifolia, Torr. & Gray Fl. II., 290. 

 A. integrifolia, Muhl. Pursh. Fl. II., 580. 



On alluvial soil in river valleys. On alluvium along Maple Creek, 

 Cypress Hills. (Macoun.) Near Milk River, on low fertile prairie 

 land, 49th parallel. (Dawson.) 



(1120.) A. artemisiaefolia, Linn. 



A. elatior, Linn. Hook. Fl. I., 309. 



A. paniculata, Michx. Hook. Fl. I., 309, in part. 



Very common as a weed along railroads, and in towns and villages, 

 throughout Canada to the Rocky Mountains. 



(1121.) A. psilostachya, DC. 



A. coronopifolia, Torr. & Gray Fl. II., 291. 

 Lake of the Woods, and westward along the 49th parallel over the 



