Soil. Best on rich, moist, sandy loams, and also grows on more 

 sterile soils than aspen. Mesophytic. 



Association. Occurs mixed with trembling aspen in reproduction 

 after fires. 



General. Not differentiated from trembling aspen in the market. 

 Like the latter it is only important because of its abundance on burned- 

 over areas. 



POPULUS BALSAMIFERA, L. 

 Balsam Poplar. Balm of Gilead. 



Size. 30 to 75 ft. by 1 to 3 ft. Often 100 ft. high. 



Growth. Rapid in youth ; longer persistent than most poplars. 



Root System. Heart to tracing. 



Crown. Open and spreading. 



Wood. Light weight, soft, fine grained. 



Reproduction. Seeds prolifically every year. Flowers in April 

 and May; the seeds' last only a short time after falling. Germination 

 percent is low and the vitality is small. 



Range. Newfoundland to Alaska, south to Maine and west to the 

 Rockies. Altitude low to medium. 



Climate. Severe; high humidity and heavy precipitation. 



Soil. Alluvial, river banks, etc. Grows in all except very wet 

 soils. 



Association. Grouped; associates with black and white spruces,, 

 birches, alders and willows. 



General. Of little commercial importance. 



POPULUS TRICHOCARPA, Torrey & Gray. 

 Black Cottonwood. Balsam Cottonwood. 



Size. Usually less than 100 feet in height. 



Growth. Rapid in the optimum and long sustained. 



Root System. Heart. 



Crown. Spreading. 



Tolerance. Intolerant. 



Wood. Like balsam poplar; 23 pounds. 



Reproduction. Prolific annual seeder flowering in April and May 

 and ripening in June and July. Low vitality but high germination per- 

 cent. Seed bed reproduction best on moist mineral soils. 



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