761 



P. deltoidea — amt. 

 Var, aurea, Van (it-rrt. 



P. cauadfusis aurea, Hurt. 

 P. vanhoutteana, Hort. 



Var. erecta. 



P. canadensis rxi-. erecta, Dip/jfJ. 

 P. monilifera rnr. erecta, Selijs. 



Var. Eugenei, Xichnh. 



P. canadensis rar. Kugenei, Hort. Zo/'sch. 



P. Eugenei, Hurl. 



P. pyramidalis /•«/•. meetensis, Mathicu. 



P. Fremontii, .S'. Wrffs. : Sargent Silva of North America 

 t. 496. California, &c. 



P. grandidentata, Mirh.r. ; Sargent Silva of North America 

 t. -t8S. North America. 



P. heterophylla, /..: Sargeitt Silva of North America t. 489. 

 North America. " Swamp Cottonwooil." 



P. argentea, Midu-.f. Hist. Arb. Am. iii. 290, t. 9. 



P. balsamifei-a, Mill, (not L.). 



P. cordifolia. Bitrgsdoi-f. 



P.. ontariensis maerophylla, Hurt. 



P. lasiocarpa, Ofirrr Icon. Phmt. t. 1943. Central Chiniu 



P. laurifolia, Lfffeh. Altai region of Southern Siberia. 

 P. balsamifera rar. laurifolia, M't's/mo'/. 

 P. balsamifera rar. viminalis, Luik/. 

 P. crispa, Hurt. 

 P. crispa Lindleyi, Hi>rl. 

 V. lindleyaua, Jinoth. 

 P. lon<:ifolia. Fi-o'h. 

 P. salioifolia. Hurt. 



