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 Salix alba Linn. White Willow. 



Range. — Europe. Widely naturalized in the United States. 



Salix alba x lucida Bebb. 



Salix fragilis Linn. Crack Willow. 



Range. — Europe. Naturalized in eastern North America. 



Salix babylonica Linn. Weeping Willow. 



Range. — Europe. Naturalized in few localities in Atlantic; region. 



Salix sitchensis Satis. Silky Willow. 



Range. — Alaska to southern California (Santa Barbara) — coast region. 



Names in use. — Silky Willow (Oreg.)j Sitka Willow (Germ. lit.). 



POPULUS Linn. 



Populus tremuloides Michx. Aspen. 



Range. — Southern Labrador to Hudson Bay (southern shores) and northwestward 

 to the Mackenzie River (near mouth) and Alaska (Yukon River); southward to 

 Pennsylvania (mountains), northeastern Missouri, southern Nebraska, and through- 

 out the western mountains to northern New Mexico and Arizona and central Cali- 

 fornia; Lower California (San Pedro Matir Mountains) and Mexico (mountains 

 of Chihuahua). 



Names in use. — Aspen (N. H., Mass., R. I., Oonn v N. Y. ? K J., Pa., 

 Del., 111., Ind., Wis., Mich., Minn., N. Dak., Nebr., Ohio, Ont., Oreg., 

 Utah, Idaho, Nev., Mont., Colo., Cal.); Quaking Asp (N. Y., Pa., Del., 

 Cal., jS". Mex., Idaho, Colo., Ariz., 111., Iowa, Minn., Mont., Nebr., Utah, 

 Oreg., Nev.); Mountain Asp (Mont.); American Aspen (Vt.); Aspen 

 Leal' (Pa.); White Poplar (Mass.); Trembling Poplar (Minn., Colo.); 

 American Poplar (Minn., Colo.); Poplar (Vt., N. Y., 111., Ind., Minn., 

 Mont.); Popple (Wis., Iowa, Mont.); Tremble (Quebec); Trembling 

 Aspen (Iowa); Aspen Poplar (Cal., Mont.). 



VARIETY DISTINGUISHED IN CULTIVATION. 



Populus tremuloides pendens Sudw. 



Populus grandidentata Michx. Largetooth Aspen. 



Range. — Nova Scotia through New Bruuswick, southern Quehec, and Ontario to 

 northern Minnesota; southward to Delaware (and along the Allegheny Mountains to 

 North Carolina, central Kentucky, and Tennessee), southern Indiana, and Illinois. 



Names in use. — Large-toothed Aspen (N. J., Pa., Del., S. C, Mich., 

 Minn.); Poplar (Me., N. H., Vt., Mass., E. I., Conn., N. Y., N. J., Pa., 

 W. Va., 1ST. C, S. C, Ga., 111., Ohio); Large toothed Poplar (JN". C); 

 Large Poplar (Tenth); White Poplar (Mass.); Popple (Me.); Large 

 American Aspen (Ala.). 



VARIETY DISTINGUISHED IN CULTIVATION. 



Populus grandidentata penduliformis Sudw. "Weeping Largetooth Aspen. 



Populus heterophylla Linn. Swamp Cottonwood. 



Range. — From Connecticut (North Gilford) and Long Island (Northport) south- 

 ward near the coast to southern Georgia; westward in the Gulf region to western 

 Louisiana aud through Arkansas to southeastern Missouri, western Kentucky, and 

 Tennessee, and southern Illinois and Indiana. 



