SALICACEAE 



Eastern Cottonwood 



Populus deltoides Bartr. 



HABIT. This important eastern species is a large tree 60- 

 100 feet high and 3-5 feet in diameter (max. 175 by 11 feet); 

 broad, open crown; large, spreading branches, 



LEAVES. Broadly deltoid; 3-6 inches long; apex acuminate; 

 coarsely crenate-serrate, teeth glandular; glabrous; petiole 

 flattened, lV^-3 inches long, with 2 glands at apex. 



FRUIT. Capsules ovoid, Yi inch long; in catkins 8-12 inches 

 long. Seed : light brown, hairy, about \{^ inch long. 



TWIGS. Stout; yellow-brown; angular; glabrous. Winter 

 buds: % inch long, conical, acute, shiny brown, resinous. 



BARK. Yellow-green and smooth on young trunks, becoming 

 thick ash-gray, and furrowed. 



Five other cottonwoods and 2 hybrids having the deltoid 

 leaves and other characters similar to P. deltoides are native 

 and distinguished in the key: 



1. Fremont cottonwood, P. fremontii S. Wats., in the southwest. 



2. Rio Grande cottonwood, P. fremontii var. wislizenzii S. Wats, in the 

 southwest. 



3. Swamp cottonwood, P. heterophylla L., in the east differs in having 

 a rounded petiole. 



4. Palmer cottonwood, P. palmeri Sarg., in western Texas. 



"j. Plains cottonwood, P. sargentii Dode, in the Great Plains. 



P. X canadensis (Alt.) Sm., the Carolina poplar, {P. deltoides x nigra) 

 is extensively planted in cities. 



P. X parryi Sarg. {P. fremontii x trichocarpa) in California. 



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