CATALOGUE OP CANADIAN PLANTS. 87 



(Buchan.) North shore of Lake Superior. (Agassiz.) Lake Mistassini, 

 N.E.T. (J. M. Macoun.) Fort Carleton, Saskatchewan Eiver. (Macoun.) 

 Cumberland House to York Factory, on Hudson Bay. (Hooker ', Fl.) 



Var. Niagarensis, Gray. 



P. Niagarensis, Tuckerman, Amer. Journ. Sci. (2, Ser.) VII., 354. 



Rapids above Niagara Falls. (Burgess.) Niagara River, near the 

 brink of the Hog's Back, growing plentifully with Udora ; and else- 

 where in the river. (Tuckerman.) 



(2445.) P. pusillus, Linn.; Gray, Man. Ed. V., 488. 



Rather common in ditches^and slow streams. In ditches at Halifax, 

 N.S. (Macoun.) Little Rocher, N.B. (Fowler, Cat.) Yicinity of 

 Ottawa. (Fletcher, Fl. Ott) Common in streams inland, from Pres- 

 cott, Ont. (Billings.) Grand Valle*e, Gasp coast, Q. ; in flowing water 

 at Hull, Q. ; in the River Trent, at Trenton, and abundant in still 

 waters and ditches throughout central Ontario. (Macoun.) Cockburn 

 Island, Georgian Bay. (J. Bell.) Jones Falls, Rideau River. (Mill- 

 man.) Little Saskatchewan, near Rapid City, and not uncommon in 

 pools in the prairie region. (Macoun.) Lake of the Woods. (Burgess.) 

 Lake Mistassini, N. E. T. (J. M. Macoun.) Specimens referred here 

 were collected at Fort McLeod, B.C., lat. 55. (Macoun.) 



Var. vulgaris, Fries.; Gray, Man. Ed. V., 489. 



This is a longer and more branching form, with generally cylindri- 

 cal and interrupted spikes. Madeline River, Gaspe", Q. ; Gull River, 

 Victoria Co. ; in deep water, .Trent River, Seymour, Northumberland 

 Co., Ont. ; Shawnigan Lake, Vancouver Island. (Macoun.) The com- 

 monest form at Ottawa. (Fletcher, Fl. Ott.) 



Var. panormitanus, Biv. 



Rideau Canal, near Ottawa. (Fletcher, Fl. Ott.) 



Mr. Morong writes of this variety : " I have carefully compared 

 these (Mr. Fletcher's specimens) with the plant sent me as P. pusillus, 

 L., var. panormitanus, Biv., and can see no essential difference. In my 

 specimens the (submerged) leaves are shorter, they are not ruddy 

 at all, and none revolute. The description of the variety, however, 

 corresponds ' leaves longer," (than the type) flaccid, the upper flower- 

 ing ones opposite and spatulate, the whole surface of the leaf with a 

 pretty chain-like areolation." I am sure that your plant meets this 

 description, and when compared as to the floating leaves the specimens 

 agree. I should not, however, regard it as^a distinct species, since it 



