4 PINACEAE. 



J 



4. P. monophylla Torr. & Frem. (Pinon.) A small tree, 5-8 

 m. high, with irregularly spreading branches and pale flaky bark; 

 leaves short, spiny-tipped, solitary, terete, 3-5 cm. long; staminate 

 cones oval with 6 involucral bracts; fruiting cones 3-6 cm. long 

 and nearly as broad, bright green, apex of scale thickened, 4-angled, 

 narrowed into a prominent knob with a usually truncate umbo 

 ending in a minute incurved tip; seeds oblong, 12-20 mm. long; 

 wing light brown, 8-12 mm. wide, remaining attached to the scale. 



Frequent on the desert slopes of the San Gabriel and San Bernar- 

 dino Mountains. 



5. P. torreyana Parry. (Del Mar or Torrey Pine.) A small 

 tree, 6-10 m. high, wdth spreading branches and dark brownish 

 bark; leaves 5 in a cluster, crowded at the ends of the thick branch- 

 lets, stout, 20-28 cm. long; staminate cones cyclindric, about 5 cm. 

 long and 8 mm. thick, involucral bracts 14; fruiting cones broadly 

 ovate, 10-15 cm. long, chocolate brown; scales much thickened at 

 apex into broad straight or reflexed umbos terminating in minute 

 spines; seeds oval, 16-20 mm. long, nearly enclosed by the thickened 

 rim of the dark brown wings, these 8-10 mm. wdde. 



Delmar, San Diego County; Santa Rosa Island. This is the 

 rarest species of pines. 



6. P. ponderosa Dougl. (Yellow Pine.) A large tree with 

 very thick red-brown bark; deeply furrowed and split in large plates; 

 leaves 3 in each cluster on stout branchlets, dark green, 15-25 cm. 

 long; staminate cones cylindric, 35-50 mm. long, involucral bracts 

 10-12; fruiting cones oval, 7-12 cm. long, rich brown; scales thick- 

 ened into a central knob terminating in compressed straight or 

 recurved umbos, awned with slender spines; seeds ovate, acute, 

 about 8 mm. long, coat nearly black, rugose; wing thin, pale brown, 

 25-30 mm. long and about 20 mm. wide below the middle. 



Common on all our mountains, making up a greater part of the 

 coniferous forests. The cones usually fall during the autumn and 

 winter after maturity. 



7. P. Jeffrey! Oreg. Com. (Jeffrey Pine.) Closely resembling 

 the preceding in foliage and habit; bark deeply furrowed, not split 

 in large plates, dark; staminate cones 3 cm. long; fruiting cones 

 oval, rather rich brown, 15-30 cm. long; seeds 8-10 mm. long; wings 

 about 25 mm. long. 



With the last, but much less common. Rather frequent in the 

 San Bernardino Mountains, especially about Bear Valley. Dis- 

 tinguished from ponderosa by the glaucous twigs, bluish tinge to 

 leaves, and large cones. 



8. P. attenuata Lemmon. (Knob-cone Pine.) A small tree 

 usually less than 10 m. high, somewhat irregularly branched; bark 

 light brown, roughish; leaves in clusters of 3, 10-15 cm. long, dark 

 green; staminate cones, cylindric, 14-15 cm. long, with 6 involucral 

 bracts; fruiting cones clustered in verticils, persistent for many 

 years, light chestnut-brown becoming grayish, elongated-conic, 

 oblique at the base, 8-14 cm. long; scales armed with stout prickles; 

 seeds black, grooved, 6 mm. long; wing 14-16 mm. long, widest near 

 the middle. (P. tuherculata Gordon.) 



