GYMNOSPERMS ON STANFORD GROUNDS ABRAMS 89 



Umbo without or with a rudimentary prickle. 



Leaves slender, drooping, 8-10 inches long; cones cylindric, 4-8 

 inches long; apophysis low-pyramidal. 



13. P. canariensis. 

 Leaves not drooping, 4-6 inches long, dark green; cones ovate 



and unsymmetrical ; apophysis on the outside rounded. 



14. P. radiata. 

 Leaves in 2s. 



Cones unsymmetrical; scales much enlarged on the outside; armed 



with prominent prickles. 15. P. muricata. 



Cones nearly symmetrical; prickles none or inconspicuous. 



Leaves slender and flexible, 2-4 inches long; apophysis flattened, 



deep, lustrous brown. 16. P. halepensis. 



Leaves stout and rigid. 



Cones and leaves 4 inches long or more. 



Seeds ^ inch long, with a very short wing; apophysis low, 



somewhat 6-sided. 17. P. Pinea. 



Seeds scarcely ^ inch long, much shorter than the wings; 

 apophysis pyramidal and sharply keeled. 



18. P. Pinaster. 



Cones and leaves 1^2-3 inches long. 

 Trees of good size. 



Leaves flattened; cone-scales with a flattened apex projecting 



beyond the dorsal umbo. 19. P. sylvestris 



Leaves rounded on the back, grooved beneath, 2-3 inches 

 long; apex of scale not projecting. 



20. P. nigra. 



Low dwarf shrub with dense foliage of dull green leaves. 



21. P. montana. 



1. Pinus excelsa Wall. 



Branchlets greenish brown, glabrous, glaucous; leaves very slender, 

 flaccid, drooping, grayish green, 6-8 inches long; cones on stalks 1-2 inches 

 long, cylindric, 6-10 inches long; scales sharp-pointed; seeds Y$ inch long; 

 wings 1 inch long, acute. 



A native of the Himalaya Mountains, where it attains a height of 150 

 feet. One tree is in the Arboretum northeast of the Cactus Garden. 



2. Pinus Strobus L. White Pine. 



Branchlets glabrous, green or greenish brown; leaves soft and very 

 flexible, 2-5 inches long, light bluish green; cones on stalks l / 2 -\ inch long, 



