ENUMERATION OF CONIFERS 



321 



with more elongated apex; seed }/i inch long. British Columbia to Mexico, 

 east to South Dakota. — Introduced to Great Britain in 1827. Hardy in 

 sheltered positions as far north as Massachusetts. One of the tallest pines 

 and most important timber trees of the Western States. 



Var. pendula, H. \V. Sarg. 

 A form with drooping branches. 



Var. scopulorum, Engelm. 

 (P. scopulorum, Lemm.), 

 Rocky Mountain Yellow P., 

 is a geographical variety, smal- 

 ler in every part; usually to 75 

 feet tall, with 

 nearly black 

 furrowed bark: 

 leaves 3-6 in- 

 ches long, some- 

 times in 2's: 

 cones smaller, 

 ovoid. South 

 Dakota to 

 Mexico and 

 Texas. — Some- 

 what hardier 

 than the type. 



Var. arizon- 

 ica, Shaw (P. arizonica, En- 

 gelm.). Arizona P. Tree to 

 100 feet tall : leaves 3-5, rigid, 

 5-7 inches long, dark green: 

 cones 2-23^ inches long, with 

 recurved prickles. Southern 

 Arizona and New Mexico. — ■ 

 Doubtful whether in cultiva- 

 tion and probably hardy only 

 in the Southern States. 



Related species are the fol- 

 lowing : P. Montezumae, Lamb. 

 (P. Gordoniana, Hartw. P. 

 Grenvilleoe, Gord. P. macro- 

 phylla, Lindl.). Tree to 100 

 feet tall or more: leaves usually 

 in fascicles of 5, but varying 



