Barton's proposed flora was never written, but Pursh, who then moved to London, England, did make a major contribution to North American botany in his Flora americae septentrionalis; or A Systematic Arrangement and Description of The Plants of North America, published in 1813. He then returned to America, moving to Canada in 1816. He botanized a great deal in Quebec, but all the material he accumulated was destroyed by fire before it could be organized into suitable form for publication. His hopes of carrying out further major work were prevented by ill health due to alcoholism.
He was so destitute when he died in Montreal that his funeral expenses had to be defrayed by his friends. His remains lay in the Papineau Road cemetery until 1857, when they were moved to the Mount Royal Cemetery. A proper monument was paid for by subscription. It read as follows:
Frederick Pursh, Obt. 1820, AEt. 46. Erected By Members of the Natural History Society of Montreal 1878.
His name is commemorated in the genus Purshia (Bitterbush) and in several species, e.g., Rhamnus purshiana.
