64 MISCELLANEOUS CIRCULAR 92, U. S. DEPT. OF AGRICULTURE 



Populus acuminata rehderi Sargent. 

 Range. — Southeastern New Mexico. 



X Populus andrewsii Sargent. 36 Hybrid. 



Range. — Known only from a cultivated tree growing near Boulder, Colorado. 

 Note on nomenclature. — Supposed to be a hybrid between Populus acumi- 

 nata Rydberg and Populus sargentii Dode. 



Populus angustifolia pJames. 37 Narrowleaf Cottonwood. 



Range. — From southern Alberta to South Dakota (Black Hills) and north- 

 western Nebraska (Hat Creek); southward in the mountain regions to Wash- 

 ington (Yakima County), central Nevada, New Mexico (vicnity of Silver City), 

 northern and southern Arizona (Santa Catalina Mountains) ; Mexico (Chihuahua). 



Note on nomenclature. — Designated also as Populus fortissima A. Nelson 

 and Macbride. 



NAMES IN USE 



Black Cottonwood (N. Mex., Utah, Balsam (Mont.). 



Colo.). Cottonwood (Idaho, Colo.). 



Narrowleaved Cottonwood (Colo., Willow Cottonwood (Idaho). 



Utah). Bitter Cottonwood (Idaho). 



Narrow-leaved Poplar (Mont., Utah). Willow-leaved Cottonwood (Mont.). 



Populus arizonica Sargent. 38 Arizona Cottonwood. 



Range. — New Mexico (in and near Silver City); Arizona (Santa Catalina 

 Mountains; planted in and near Tucson, Pima County, and at Douglas, Cochise 

 County; in Yavapai County near Clarksdale, Camp Verde, and Gannett Creek 

 in vicinity of Prescott; along Salt River, near the Roosevelt Dam and Gila 

 Creek, near Flagstaff). 39 



Note on nomenclature. — Formerly designated as Populus mexicana West- 

 mael, a Mexican species which is not known to occur within our border. 



NAME in use 



Arizona Cottonwood 



*Populus deltoides Marshall. Eastern Cottonwood. 



Range. — From Vermont (Lake Champlain); western New York; Pennsyl- 

 vania (Northampton County); Maryland (Bare Hill, Baltimore County; Mont- 

 gomery County, north bank of Potomac River opposite Plummer Island, several 

 miles north of Washington, D. C.) ; central-eastern Mississippi (Lowndes County, 

 in the vicinity of Artesia; Oktibbeha County, in the vicinity of Starkville). 

 Range imperfectly known at present. 



Note on nomenclature. — Formerly long designated as Populus monilifera 

 Aiton. It is the tree described as Populus angulata Michaux f. Recently some 

 authors have applied Populus balsamifera Linnaeus to it, which in the writer's 

 opinion can not apply. 



names in use 



Cottonwood. Eastern Cottonwood (lit.). 



38 According to C. S. Sargent (Trees and Shrubs, II, 212, 1913), this tree was grown from cuttings taken 

 from a wild tree found near Boulder, Colo., by E. H. Andrews, in whose nursery the cultivated tree is 

 standing. Another tree growing at Walsenberg, Huerfano County, Colo., is believed to be of the same 

 origin. 



37 Britton and Shafer (op. cit., 173, fig. 129) include in this sequence as a new species Populus Tweedyi 

 Britton, which the writer has not seen, but which appears to be very distinct from other cottonwoods in 

 the form of its leaves and fruit capsules. It was discovered by Frank Tweedy in 1901 at Encampment, 

 Carbon County, southern Wyoming. 



38 A Mexican variety of this species has been distinguished as Populus arizonica jonesii Sargent, which 

 occurs in the valley of Palms, near Chihuahua, and Saltillo and at Piedras Negras (Sargent). 



39 Possibly occurring also on Mill Creek above Forest Home, San Bernardino Mountains (Sargent). In 

 1899 the writer saw a number of trees in the Owens River Valley west of Lone Pine which are now beb'tved 

 to be of this species. These trees were seen at some distance. 



