THE COTTONWOODS: POPLARS 



TECHNICALLY speaking we have no Cottonwoods, but 

 there are nine species of trees indigenous to the United 

 States that are generally known as Cottonwoods ; yet 

 botanically they, together with two others, are Poplars, and 

 to persist in calling these nine species Poplars would lead 

 to confusion in the minds of those not familiar with botan- 

 ical nomenclature. The two species of Poplars not classed 

 as Cottonwoods are commonly called Aspens. They are 

 Trembling Aspen (Populus tremuloides) and Largetooth 

 Aspen (Populus grandidentata). It is seldom that either 

 of these grows large enough in the United States to be of 

 value for saw timber, and at best they are worth but little 

 for that, yet they are considered the most valuable of any of 

 our woods for paper pulp. It is only in the extreme north- 

 ern portion of our country that they attain a size to make 

 artificial cultivation a profitable undertaking. They repro- 

 duce themselves abundantly whenever offered an opportun- 

 ity, even to the extent of becoming a nuisance by crowding 

 out more valuable species ; hence they will not be further 

 considered here. 



There is one feature common to all the Poplars and Cot- 

 tonwoods. The stem of the leaf botanically, the petiole 

 is flat and its face is at right angles with the face of the 

 leaf, and this permits a slight wind to cause the leaf to vi- 

 brate, hence " Trembling Aspen." Three species of Cotton- 

 woods are, to some extent, manufactured into lumber, but 

 as there is little difference in them a consideration of one 

 will substantially cover all, notation being made where they 

 differ. These are known as Swamp Cottonwood (Populus 

 heterophylla), Balm of Gilead (Populus balsamifera\ and 

 Cottonwood (Populus deltoides). The last species is best 

 known and most important. For a long time it was known 



