19Q MISC. PUBLICATION 303, U. S. DEPT. OF AGRICULTURE 



A large evergreen tree ; five-needled ; adapted to many kinds of soil ; seedlings 

 form large taproots; difficult to transplant; very intolerant of shade; sus- 

 ceptible to blister rust; most seed is produced by trees in open stands at low 

 altitudes ; long-lived ; wood soft, of value commercially ; 5,400-5,600 seeds per 

 pound, germination 36 percent. 



Stomach records: Two species of birds, including grouse. Observations: 

 Porcupine, spruce squirrel, Fremont squirrel ; much eaten by birds and squirrels 

 generally. 



Pinus glabra Walt. Spruce pine. 



Range : 29, 30. 



Site: well-drained, moist, sun, shade. 

 Fruit: Cone. 



A large evergreen tree ; two-needled ; growth remarkably rapid ; wood soft, 

 of some value commercially ; 77,500 seeds per pound. 

 Stomach records: Bobwhite, squirrel. 



Pinus heterophylla, see P. caribaea. ' 



Pinus jeffreyi Murr. Jeffrey pine. 



P. ponderosa jeffreyi Vasey. 

 Range : 4. 



Site: Well-drained, sun. 

 Fruit: Cone. 



A large evergreen tree; three-needled; appears to intergrade with P. pon- 

 derosa; tolerant of shade in early stages, later intolerant ; produces seed pro- 

 lifically; wood of great commercial value; 3,100-3,300 seeds per pound; seeds 

 from large cones complete their germination 2 weeks before seeds from small 

 cones. 



Stomach records: Four species of birds, including quail and Mount Pinos 

 grouse. Observations: Clark's nutcracker; Columbian gray squirrel, Sierra 

 chickaree, Tahoe chipmunk, Allen's chipmunk ; commonly much eaten by birds 

 and rodents ; of slight importance as browse for mule deer. 



Pinus lambertiana Dougl. Sugar pine. 



Range: 1, 4, 10. 

 Site: Well-drained, sun. 

 Fruit : Cone ; ripe in August of the second season, seeds shed in October, 



cones falling the following year. 



A very large evergreen tree ; largest of all pines ; flve-needled ; susceptible to 

 blister rust ; very intolerant of shade except in the seedling stage ; wood soft, 

 of high commercial value ; 2,300 seeds per pound, germination 65 percent. 



Observations: Porcupine, Columbian gray fox, Sierra chickaree, Allen's chip- 

 munk, long-eared chipmunk, California gray squirrel; of slight importance as 

 browse for mule deer. 



Pinus lasiocarpa, see Abies lasiocarpa. 



Pinus leiophylla Schlecht. and Cham. Chihuahua pine. 



P. chihuahuana Engelm., P. leiophylla chihuahuana Shaw. 

 Range: 11, 14. 



Site : Dry, well-drained, moist, sun. 

 Fruit : Cone ; mature in September of the third season, often persistent 



closed 5 or more years. 



A large evergreen tree ; commonly three-needled ; intolerant of shade ; wood 

 of importance commercially but only a small supply is known. 

 Observations: Much eaten by thick-billed parrots. 



Pinus mitis, see Pinus echinata. 



Pinus monophylla Torr. and Frem. Singleleaf pinon. 



P. cembroides monophylla Voss., Caryopitys monophylla (Torr. and Frem.) 

 Rydb. 



Range : 4, 5, 9, 10, 13, 14. 



Site: Dry, well-drained, sun. 



Fruit : Cone ; mature in August of the second season, seeds shed in 



September. 



A small to large, flat-topped evergreen tree ; commonly one-needled ; very local 

 in occurrence; endures extreme drought in its native habitat; very slow grow- 

 ing; intolerant of shade; wood much used for fuel locally; 1,200 seeds per 

 pound. 



