A Guide to the Poisonous Plants and 



Weed Seeds of Canada and the 



Northern United States 



By 



R! E. Thomson, B.A., F.R.S.C. 



Associate Professor of Phanerogamic Botany 

 and 



H. B. Sifton, M.A. 



Assistant Professor of Research in Botany 



UNIVERSITY OF TORONTO IM< 

 1922 



