Contributions to Canadian Botany. 205 



A. BLITOIDES, Wat. 



London, Ont. (Millman.) Port Colborne, Ont. (John 



Macoun.) Point Fxiwaid, St. Clair Kiver, Ont. (Jos. M. 



Macoun.^ 



POLYGONUM. 



All our herbariom specimens of this genus have been ex- 

 amined by Prof. John K. Small, who has made several im- 

 portant changes iu our determinations. He had not our 

 herbarium sheets at the time his revision of the Poly- 

 gonacece was published so that the distribution of the Can- 

 adian species of Polygonum as given below will greatly ex- 

 tend the range of many Xorth American species. I follow 

 Prof. Small's arrangement of the species throughout. 



(1.) P. viviPARUM, Linn. 



Throughout Canada. Our most northern specimens are 

 from Lat. 64° 26', Long. 100° 45', 1893. {Jas. W. Tyrrell.) 

 and Great Bear Lake Eiver. Lat. 65°, 1892. {Miss E. 

 Taylor?) 



(2.) P. Pkrsicaria, Linn. 



From Prince Bdwai"d Island to Vancouver Island. 

 Abundant throughout the settled parts of Canada. 



(3.) P. Carkyi, Olney. 



Wet sandy banks, Moon River, Muskoka, Ont., 18*78. 

 (Burgess.) The only Canadian station. 



(4) P. hydropiperoides, _^ichx. 



We have this species from but one locality, Belleville, 

 Ont. Many of the references given by Prof. Macoun (Cat. 

 Can. Plants, Vol. I, p. 411), probably refer to other species. 

 This plant is certainly not of as general distribution in 

 Canada as is supposed, or our herbarium would contain 

 specimens from more stations than one. 



Of this species and var. strigosum Prof. Small writes, " P. 

 hydropiperoides, as well as the var. strigosum, has an almost 

 invariable character which it seems, has never been re- 

 coi-ded. The stem or bi^anche-^ always produce, at the di.**- 



