ENUMERATION OF CONIFERS 309 



a round-topped head; bark irregularly divided by shallow fissures into numer- 

 ous large, thin, red-brown scales; branchlets dark orange, pubescent at first: 

 leaves usually 3, sometimes 2, slender, dark green, with stomata on all 3 

 faces, much incurved, 1-2 inches long: cone subglobose, 1-2 inches broad; 

 apophysis pyramidal, strongly keeled, lustrous brown, with broad obtuse 

 umbo; seeds oblong-obovate, ^-^4 inch long, dark brown, with very narrow 

 wing. Southern Wyoming to California, western Texas and northern Mexico. 

 — Introduced before 1830 to Germany. Like the following varieties little 

 known in the eastern States and probably not hardy north of New York. 

 A small, round-headed, often shrubby tree of slow growth. The following 

 varieties are often considered distinct species, but they are connected with 

 the type and each other by intermediate forms. 



Var. monophylla, Voss (P. monophylla, Torr. & Frem. P. Fremontiana, 

 Endl.). SiNGLELEAF P. Tree occasionally to 40 or 50 feet tall; branchlets 

 light orange, glabrous: leaves usually solitary, sometimes 2, rigid, spinescent, 

 ^/i-\}/2 inches long, glaucous-green: cone broadly ovoid, the apophysis de- 

 pressed-pyramidal, ridged, the flattened umbo with a minute incurved tip. 

 California to Colorado and Arizona. — Introduced in 1848 to Europe. Hardy 

 as far north as Massachusetts. 



Var. edulis, Voss {P. edulis, Engelm, Caryopitys edvlis. Small). Nut P. 

 Tree often to 50 feet tall; branchlets light yellowish-brown, puberulous at 

 first: leaves 2-3, rigid, dark green, '^/i-V/i inches long: cone broad-ovoid, the 

 apophyses pyramidal, umbo with minute recurved tip. Colorado to New 

 Mexico. — Hardy as far north as Massachusetts. 



Var, Parryana, Voss {P. Parryana, Engelm. P. quadrifolia, Sudw.). 

 Parry P. Tree of pyramidal habit, to 40 feet tall, round-topped in old age; 

 branchlets puberulous, light grayish-brown: leaves 3-5, usually 4, rigid, 

 incurved, l3^2~l/<t inches long, pale glaucous-green: cone subglobose; the 

 apophyses pyramidal, umbo with minute recurved prickle. California. — 

 Probably not hardy north of the Middle Atlantic States. 



To this group also belong two Mexican species: P. Pmceana, Gord,, with 

 the leaves in clusters of 3 and with cylindric cone, and P. Nelsonii, Shaw, 

 fascicles with 3 partly connate serrulate leaves and a persistent sheath; 

 cone cylindric. They are probably not now in cultivation and could be ex- 

 pected to be hardy only in the Southern States and southern California. 



Group 5. Gerardian^ 

 Seed with a very short articulate wing: leaves 3, serrulate. 



14. P. Bungeana, Zucc. Lace-Bark P, Tree to 80 or 100 feet tall, with 

 long and slender branches; bark exfoliating in large, thin, irregular plates, 

 leaving particolored areas, light gray, on old trees chalky- white; young 



