CATALOGUE OF CANADIAN PLANTS. -457 



Var. cand leans, Gray. 



P. candicans, Ait. Pursh. Fl. I., 618. 



Planted for ornament in JSTew Brunswick. (Fowler's Cat.) Vicinity 

 of Campbellton, N. B. (Chalmers.) Apparently wild in the neighbor- 

 hood of Pictou, KS. Both petioles and upper surface of the leaves 

 hairy. In Ontario this variety seems to be the prevailing form, if the 

 hairy petiole and veins of the upper surface of the leaf constitute, with 

 the heart-shaped, short pointed leaves, the separating characters. 

 (Macoun.) One small tree detected below Niagara Falls, on the Cana- 

 dian side, near the water's edge. Probably of natural growth. (David 

 F. Bay.) 



(2056.) P, angustifolia, James. Black Cottonwood, 



P. balsamifera, var. angustifolia, Wat. Macoun's Cat. No. 1675- 



In the south-western part of the prairie region along the Milk and 

 Belly rivers and their tributaries, near Lat. 49°. (Dawson.) Common 

 in the Bow Eiver valley from the Blackfoot Crossing to the Eocky 

 Mountains. Easily known by its very narrow long pointed leaves. 

 (3Iacouji.) 



(2057.) P. trichocarpa, Torr. & Gray. 



P. balsamifera. var. Hook. Fl. II., 154. 



P. balsamifera, Lyall. in Jour. Linnjean Soc. VII., 134. 



Common in the Columbia valley at Donald, and westward through 

 the low valleys of the Selkirk Mountains. (Macoun.) Valley of the 

 Fraser Eiver and probably further north. (Sargent.) There is some 

 ditticulty in separating this tree (a western form), from P. monilifti'a 

 and P. balsamifera in the northern and north-eastern part of British 

 Columbia. While it certainly occurs in the valley of the Lower Fraser 

 we have no notice of its occurrence along the river above Yale. 

 (Daioson.) 



(2058.) P. moniiifera, Alton. Cottonwood. 



P. angulata, Ait. Pursh. Fl. I., 619. 



P. lievigata, Ait. Pursh. Fl. I., 619. 



P. angulosa, Michx. Fl. II., 243. 



P. Canadensis, Michx. N. American Sylva II. Ill, 1819. 



Ste. Anne, Champlain Co., and Lotbiniere, Q. (St. Cyr.) Vicinity 

 of Montreal, 1821. (Holmes.) At Billings Bridge, and other places 

 along the Eideau, near Ottawa. [Fletcher.) In ditches along the 

 Grand Trunk railway for its whole length in Ontario. All young 

 trees produced from western seed, carried by the cars. Large trees in 



