PINACEAE (PINE FAMILY) 27 



tary in No. 5), united at the base by a sheath formed from the bud-scales. 

 Cones large, the scales becoming thick and woody and bearing two seeds on the 

 base of each scale, not maturing til) the second year. 



Leaves 5 in each fascicle; seeds winged. 

 Scales not tipped with a prickle. 



Cones narrowly ovoid or subcylindrical; the scales separating at 



maturity and discharging their seeds . . . . .1. P. flexilis. 



Cones ovoid; their scales remaining closed at maturity . . 2. P. albicaulis. 

 Scales tipped with a prickle . . . . . . . 3. P. aristata. 



Leaves in fascicles of 2-3 (rarely 1); scales usually spiny-tipped; seeds 



winged or wingless. 

 Leaves 4-7 cm. long. 



Leaves subterete or triangular with smooth edges; seeds wingless. 



Two leaves in each fascicle 4. P. edulis. 



Some or most of the fascicles reduced to one leaf . . . 5. P. monophylla. 

 Leaves regularly in pairs, semiterete, with flat faces and serrulate 



edges . . . . . . . . . . . 6. P. Murrayana. 



Leaves 10-18 cm. long . . . . . . . . 7. P. scopulorum. 



1. Pinus flexilis James, Long's Exp. 2: 34. 1823. A tree with furrowed 

 gray bark, short trunk, 5-10 dm. in diameter, freely branched upward, becom- 

 ing 12-25 m. high: leaves in fascicles of 5, 4-7 cm. long, rather stout and 

 rigid: cones narrowly ovoid to subcylindrical, greenish, 8-15 cm. long; the 

 scales unarmed, broad, moderately thickened at the ends, opening at maturity 

 and the seeds soon falling out. (Apinus flexilis Rydb. Bull. Torr. Bot. Club 

 32: 598. 1905.) LIMBER PINE. On wind-swept ridges and slopes, situations 

 to which its remarkably flexible branches adapt it; at high elevations much 

 reduced in size, or depressed; New Mexico to Montana and westward. 



2. Pinus albicaulis Engelm. Trans. Acad. Sci. St. Louis 2: 209. 1868. 

 Very similar to the preceding in aspect: cones oval or subglobose, sessile, 

 dark purple; the scales with thickened ends, often sharp-beaked, but not 

 awned, remaining closed at maturity. . (Apinus albicaulis Rydb. 1. c.) WHITE- 

 BARK PINE. Usually lower and with more rounded head than the preceding; 

 from middle elevations to timber line; northwestern Wyoming, far northward 

 and westward. 



3. Pinus aristata Engelm. Am. Journ. Sci. II. 34: 331. 1862. A tree 

 12-15 m. high, 4-7 dm. in diameter, in alpine stations usually much dwarfed: 

 leaves in fascicles of 5, erect, curving, 3-angled, smooth, submucronate, 

 green, each side with a white glaucous stripe : cones violet-brown, narrowly 

 ovoid, resinous, 7-10 cm. long; scales with thickened rhombic ends, with small 

 beak and tipped with a lanceolate-subulate often recurved awn, opening and 

 discharging the seeds. BRISTLE-CONE PINE. Subalpine; from Colorado to 

 Nevada and California. 



4. Pinus edulis Engelm. Bot. Wisliz. Rep. 88. 1848. A low round-topped 

 tree branched from or near the base, 4-6 m. high: leaves mostly in pairs 

 (rarely in threes), 3-5 cm. long, rigid, curved or nearly straight, spreading: 

 cones sessile, subglobose, about 5 cm. long; the tips of the scales thick, trun- 

 cate, raised-pyramidal but without awns or prickles: seeds large, brown, 

 wingless, edible. (Caryopitys edulis Small, Fl. S. U. S. 29. 1903.) PINON 

 or NUT PINE. From Texas and Colorado to Utah and Arizona. 



5. Pinus monophylla Torr. & Frem. Fremont's 2d Rep. 319, t. 4. 1845. 

 Closely resembling the preceding: leaves usually only one from each sheath. 

 (Caryopitys monophylla Rydb. 1. c. 597.) SINGLE-LEAF PINON. rFrom the 

 Wasatch in Utah to Nevada and Arizona. 



6. Pinus Murrayana Oreg. Com. in Murray Rep. Bot. Exp. Oreg. No. 740, 

 t. 3. 1853. Usually growing in dense groves or forests and then tall (15- 

 30 m.) and very slender, nearly devoid of branches except at the summit; if 

 growing in more open ground, more freely branched and stockier: leaves semi- 

 terete, rather rigid, about 5 cm. long: cones small, adhering tenaciously to the 

 branches, which are often marked by the dead, persistent cones of the previous 

 years; scales closely compacted, with quadrangular ends, armed with slender 

 more or less recurved prickles which are often deciduous: seeds red-brown, 

 winged. LODGE POLE PINE. Used to some extent for lumber, but especially 



