NATIVE WOODY PLANTS OF THE UNITED STATES 185 
Picea canadensis (Mill.) B. S. P. White spruce. 
P. glauca (Moench.) Voss., P. alba Link. 
Range: 12, 15 (Black Hills), 21, 23, 24, 26, 27. 
Site: Well-drained, sun, shade. 
Fruit: Cone; seeds shed in September, cones soon falling. 
A large evergreen tree; root system shallow and spreading; wood of great 
importance commercialiy ; seed produced locally every year but heavy seed pro- 
duction occurs at intervals of 5 to 8 years; vitality of seed persistent; 180,000— 
230,000 seeds per pound. ‘Ten horticultural varieties are in cultivation; long- 
lived. 
Stomach records: Crossbill ; mountain sheep, plains white-tailed deer. Obdserva- 
tions: Hight species of birds; porcupine, red squirrel, moose; casually browsed by 
northern white-tailed deer. 
Picea engelmannii (Parry) Engelm. Engelmann spruce. 
P. parryana Sarg. 
Range: 4, 9, 11, 12, 18, 14, 15. 
Site: Dry, well-drained, moist, sun, shade. 
Fruit: Cone; mature in August, seeds shed by October, cones falling 
by spring. 
A large evergreen tree; root system shallow; growth fair on dry soil; long- 
lived; wood much used commercially; 0.5 pound of seed per bushel of cones, 
69,000-376,000 seeds per pound; germination 34-68 percent; seeds produced in 
quantity locally about every 3 years; seed vitality persistent, as much as 30-50 
percent after 5 years when properly stored. 
Stomach record: Three species of birds, including dusky grouse; black-tailed 
deer, plains white-tailed deer. Observations: Red squirrel, porcupine, bighorn. 
Picea glauca, see Picea canadensis. 
Picea mariana (Miill.) B. S. P. Black spruce. 
P. mariana brevifetia Rehd. 
Range: 238, 24, 26, 27. 
Site: Well-drained, moist, sun, shade. 
Fruit: Cone; mature in August, persistent many years. 
A large evergreen tree; commonly most abundant on acid soils; root system 
shallow and widespreading; slow growing; Somewhat damaged by insects and 
fungi; wood of little importance commercially; seeds produced abundantly at 
irregular intervals; 540,000 seeds per pound, vitality persistent; prostrate 
branches often root. 
Stomach records: Blue heron, crossbill. Observations: Seven species of birds; 
snowshoe hare, porcupine. 
Picea parryana, see Picea engelmannii and P. pungens. 
Picea pungens Hngelm. Blue spruce. 
P. parryana (Andre) Parry. 
Range: 9, 12, 18, 14. 
Site: Well-drained, moist, sun. 
Fruit: Cone; available in August, seeds shed in September, most cones 
persistent until the following autumn. 
A large evergreen tree; root system shallow in wet soils; deeper in dry soils; 
long-lived; wood of least value commercially of the spruces; abundant seed 
crops produced every 2 or 3 years; 80,000-130,000 seeds per pound, germination 
48-7 percent, vitality long persistent ; brilliant color of forms (as Koster spruce)! 
gradually lost with age. 
Stomach records: Black-tailed deer. Observations: Three species of birds. 
Picea rubens, see Picea rubra. 
Picea rubra Link. Red spruce. 
P. rubens Sarg. 
Range: 27. 
Site: Well-drained, moist, sun, shade. 
Fruit: Cone; available in September, most seeds falling by late fall, 
a few the following spring. 
