CHECK LIST OF FOREST TREES 



61 



Aspen (N. H., Mat 

 N. Y., N. J., Pa 

 Wis., Mich., Minn. 



Quaking Asp (N. Y., 



Iowa, Minn.). 



American Aspen (Vt.). 



Aspen Leaf (Pa.). 



White Poplar (Mass.). 



NAMES IN USE 



, R. I., Conn., Trembling Poplar (Minn.). 

 Del., 111., Ind., American Poplar (Minn.). 

 Ohio, Ontario). Poplar (Vt., N. Y., 111., Minn.). 

 Pa., Del., 111., Popple (Wis., Iowa). 

 Tremble (Quebec). 

 ^Trembling Aspen (Iowa). 



Quaking Aspen (lit. and hort.). 

 Quiver-leaf. 



VARIETY DISTINGUISHED IN CULTIVATION 



Populus tremuloides pendens Sudworth. 



Weeping Aspen. 



Populus tremuloides vancouveriana (Trelease) Sargent. 30 



Vancouver Aspen. 



Range. — Believed to be limited in its range to the region west of the Cascade 

 Mountains from Vancouver Island, British Columbia, southward to the heai of 

 Puget Sound; occurring also in Oregon (Washington and Benton Counties). 

 Frequent in the coast region of Vancouver Island. 



Note on nomenclature. — Originally described as Populus vancouveriana 

 Trelease. 31 



name in use 

 Vancouver Aspen 



*Populus tremuloides aurea (Tidestrom) Daniels. 32 Aspen. 



Range. — From the Yukon River to Saskatchewan and southward in the Rocky 

 Mountain region to southern New Mexico and Arizona (mountains); westward 

 to British Columbia (Skena River), western Washington and Oregon, California 

 (Sierra Nevada and southern mountains); southward into Mexico (Sierra de 

 Laguna, Lower California, and in the mountains of Chihuahua and Sonora); 

 eastward to the Dakotas and western Nebraska. 



•Note on nomenclature. — First described in 1911 as Populus aurea Tidestrom, 

 prior to which it was not considered distinct from the ordinary forms of Populus 

 tremuloides Michaux. 



NAMES in use 



Golden Aspen. 



Aspen (N. Dak., Nebr., Oreg., Utah, 



Idaho, Nev., Mont., Colo., Calif.). 

 Quaking Asp (Calif., N. Mex., Idaho, 



Colo., Ariz., Mont., Nebr., Utah, 



Oreg., Nev.). 



Mountain Asp (Mont.). 



Trembling Poplar (Colo.). 



American Poplar (Colo.). 



Poplar (Mont.). 



Popple (Mont.). 



Aspen Poplar (Calif., Mont.). 



Populus tremuloides cercidiphylla (Britton) Sudworth. 



Aspen. 



Range. — Western Wyoming (upper basin of Hoback River). 

 Note on nomenclature. — Originallv described as Populus cercidiphylla 

 Britton^ 3 



NAMES IN USE 



Roundleaf Aspen. 



Aspen. 



3° David Lyall appears to have been the first explorer to discover this tree in Vancouver Island, where 

 he found it in 1858-59, since which time it has not been considered specifically or varietally distinct from 

 Populus tremuloides Michaux. 



31 Apud Tidestrom in Piper and Beattie, Flora Northwest Const, 118, 1915. 



« Univ. Mo. Studies, II, 98, 1911. This variety is distinguished from the species from the fact that its 

 leaves turn a golden yellow or orange in autumn, while in the species they become pale lemon yellow. 



" In Britton and Shafer, North Am. Trees, 180, 1908. 



