COMPOSITAE THISTLE FAMILY FLEABANE 777 



the style more or less flattened with short appendages; achenes pubescent and 

 2-nerved; pappus a single row of fine capillary bristles. 



About 120 species of wide distribution, most numerous in North America. 

 Several species of fleabane (. philadelphicus, E. annuus and E. canadensis) 

 are used in medicine. They are reputed diuretics, tonics and astringents. 



Fig. A. Small Horseweed (Erigeron 

 divaricatus). From Indiana to Minne- 

 sota to Nebraska and southward. Com- 

 mon in sterile grounds. (Charlotte M. 

 King). 



Fig. B. Horseweed, Mares' Tail (r- 

 igeron canadensis). A common weed 

 throughout the United States, especially 

 northward, also in Europe. Acrid said 

 to be irritating. (Charlotte M. King). 



Erigeron catwdensis L. Horseweed 



Bristly herb, stem hairy or somewhat glabrate, 1-6 feet high, simple or 

 paniculately branched ; leaves usually pubescent or ciliate, the lower spatulate, 

 incised or entire, obtuse or acutish, the upper generally linear and entire; heads 

 numerous, with inconspicuous white ray flowers shorter than the pappus ; achenes 

 small, flattened; pappus of numerous small fragile bristles. 



Distribution. Common throughout the eastern part of North America 

 except far northward. Common also in the Rocky Mountain region, and in 



