310 THE CULTIVATED EVERGREENS 



branches grayish-green, glabrous: leaves rigid, acute, light green, 2-4 inches 

 long, with stomata on the back: cones almost sessile, conic-ovate, light yel- 

 lowish-brown, 2-3 inches long; apophysis much broader than high, ridged, 

 with a triangular pointed and recurved umbo; seed dark brown, with narrow 

 wing, }/i-}/2 inch long. Northwestern China. — Introduced to Great Britain in 

 1846 from the neighborhood of Peking, where it had been cultivated since 

 ancient times. Hardy as far north as Massachusetts. A slow-growing tree 

 usually of bushy habit in cultivation and with rather sparse light green 

 foliage; remarkable for its exfoliating bark resembling that of the plane- 

 tree, but of grayish color. 



The closely related Himalayan P. Gerardiana, Wall., has larger cones and 

 longer oblong-cylindric seeds. It has been repeatedly introduced to Great 

 Britain, but is at present very rare and probably not known in this country 

 where it would be hardy in the Southern States. 



Group 6. Balfourian^ 

 Seeds with long wing: leaves in fascicles of 5, entire, without stomata on 

 the back and with marginal resin-ducts; sheath gradually deciduous. 



15. P. Balfouriana, Jeffrey. Foxtail P. Tree to 40, occasionally 90 feet 

 tall, narrow-pyramidal when young, irregular and open in old age; bark on 

 stems and branches of young trees thin and smooth, milky-white, on old 

 trees thick, dark red-brown, deeply divided into broad, flat ridges covered 

 with small appressed scales; branclilets dark brown, puberulous at first: 

 leaves crowded, incurved and pressed against the branches, rigid, acute, dark 

 green on the back, with conspicuous white lines on the ventral sides, 1-1)^ 

 inches long, remaining for ten to twelve years on the branches : cones pendu- 

 lous, subcylindric, dark purplish-brown, 33^-5 inches long; apophysis flat- 

 tened, the concave oblong umbo with minute incurved prickle; seed ]/^ inch 

 long, with adnate wing. California. — Introduced in 1852 to Great Britain. 

 Hardy in sheltered positions as far north as Massachusetts. 



16. P. aristata, Engelm. {P. Balfouriana var. aristata, Engelm.). Bristle- 

 cone P. (Foxtail P.). Bushy tree occasionally to 50 feet tall, sometimes a 

 semi-prostrate shrub; similar to the preceding species; branchlets light orange 

 and almost glabrous: leaves stout or slender, dark green, 1-1 H inches long, 

 with white lines on the ventral sides, usually with conspicuous scattered 

 exudations of resin: cones cylindric-ovoid, 3-33^2 inches long; apophysis 

 elevated; umbo with a slender incurved spine to 34 inch long; seed 34 inch 

 long. California to Colorado and Arizona. — Introduced in 1861 by Dr. 

 Parry to the eastern States and Europe. Hardy as far north as Massa- 

 chusetts. In cultivation usually a handsome low shrub with ascending 

 branches densely clothed with appressed leaves sprinkled with resinous 



