NATIVE WOODY PLANTS OF THE UNITED STATES 
197 
lived; easily damaged by fire when young, less so with age; much attacked 
by fungi; easily storm damaged; fairly wind-firm; 1,300,000 seeds per pound, 
germination 60-90 percent, vitality transient ; stump sprouts and root sprouts 
produced ; has been successfully used in checking erosion and in fixation of sand 
dunes ; wood used commercially ; grows on coal-stripped lands in Illinois. 
Stomach records: Black-tailed deer. Observations: Evening, and rose-breasted 
grosbeak ; cottontail rabbit. Much browsed by cattle. 
Popuhis fremoiitii Wats. Fremont cottonwood. 
P. macdoiigaUi Rose. 
Range : 1, 3, 4, 5, 9, 10, 11, 13, 14. 
Site: Well-drained, moist, sun. 
Fruit: Capsule. 
A large tree ; commonly occurs in sandy soil ; grows well in saline soils ; 
rapid growing, short-lived ; wood used locally ; much attacked by mistletoe. 
Several varieties are described, ail occurring within the range of the species. 
Observations: California mule deer. 
Populiis grandidentata Michx. Largetooth aspen- 
Range : 21, 22, 23, 25, 26, 27, 28. 
Site: Dry, well-drained, moist, sun. 
Fruit : Capsule, available in May. 
A small to large tree; grows in sand, humus or loam; root system shallow; 
very rapid growing, short-lived ; often severely injured by fungi, fire, wind, and 
insects ; wood used commercially ; a pioneer in burned and cut-over land ; germi- 
nation percentage of seeds high, vitality transient. 
Observations: Cottontail rabbit, white-tailed deer. 
Popnlas heterophylla L. Swamp cottonwood. 
Range: 25, 27, 28, 29, 30. 
Site: Moist, sun. 
Fruit : Capsule, available in May. 
A large ti-ee ; root system very shallow ; rapid growing, short-lived ; subject 
to heart rot at maturity ; wood of importance commercially. 
Populus macdougalii, see Populus fremontii. 
Populus mesicana, see Populus arizonica. 
Populus occidentalis, see Populus sargentii. 
Populus palmeri Sarg. Palmer cottonwood. 
Range: 16, 20. 
Site : Well-drained, moist, sun. 
Fruit: Capsule. 
A large tree. 
Populus sargentii Dode. Sargent cottonwood. 
P. deltoides occidentalis Rydb., P. occidentalis (Rydb.) Britt., P. angulata 
Port, and Coult. 
Range : 12, 13, 14, 15, 16, 18, 19, 21. 
Site : Well-drained, moist, sun. 
Fruit: Capsule. 
A large tree; rapid growing, short-lived; wood used to some extent locally. 
Populus tacamaliaca, see Populus balsamifera. 
Populus texana Sarg. Texas cottonwood. 
Range: 18. 
Site: Well-drained, moist, sun. 
Fruit: Capsule. 
A large, short-lived, rapid-growing tree. 
Populus tremuloides Michx. (pi. 24, A, B,). ftuaking aspen. 
P. aurea Tidest., P. vancouveriana TreL, P. cercidiphylla Britt. 
Range : 1, 2, 4, 6, 7, 8, 9, 11, 12, 13, 14, 15, 18, 21, 22, 23, 24, 25, 26, 27. 
Site : Dry, well-drained, sun. 
Fruit : Capsule, available May- June. 
A small to large tree ; occurs in many soils ; apparently not satisfactory in 
pure plantations owing to insects and disease ; root system shallow ; will grow in 
many soils but apparently does best in sandy loam; very rapid growing, short- 
lived; easily and seriously damaged by fire, wind, fungi, and insects; wood 
