THE PINE SUB-FAMILY. 149 



hardy, but as they are all untested, we have deemed it ex- 

 pedient to place them in a separate list from the main por- 

 tion of the genus. 



78. P. albicaulis, Engelmann. " Syn. P. cembro- 

 ides, Newberry, Pac. R. R. Rep. 6, Bot., p. 44, c. ic., non 

 Zucc. An alpine species from the Cascade Mountains in 

 Oregon ; may be a western form of this species (P. flexilis, 

 James,) though I am inclined to consider it as different, 

 and intermediate between P. flexilis and P. Cembra, dis- 

 tinguished by the pubescent branchlets, few scattered 

 teeth on the edge of the leaves, and especially by the 

 short oval cones with thick squarrose scales pointed with 

 a knob. The name is suggested by the color of the bark 

 of the tree, w^hich is as white as milk.' 1 '' (Engelmann.) 



79. P. Balfouriana, Jeffrey. Has been introduced 

 into English collections, and is described as very distinct 

 and quite hardy, but not proven in the Eastern States to 

 our knowledge. It is a handsome tree 80 feet high, and 



O CJ 7 



was first seen by Jeffrey on the mountains of Northern 

 California, at elevations varying from 5,000 to 8,000 feet. 

 The leaves are mostly 5 in a sheath, but occasionally 3 

 and 4, short, rigid, numerous, and glaucous below. 

 Branches, very flexible and drooping. Cones, very resin- 

 ous, pendulous, brown, with medium-sized seeds. 



80. P. Frieseana, says the Regensburger Flora, " was 

 called after the eminent botanist at the University of Up- 

 sula, Sweden, and is the Pine of Laponia, which Linnaeus 

 and Wahlenburg, without any other comment, classified 

 with P. sylvestris. It differs, however, from the latter, 

 in being found at higher elevations than the Abies ex- 

 celsa, whilst P. sylvestris is generally found on lower ones. 

 The bark of P. Frieseana is likewise cracked, but does 

 not scale off like that of the Scotch Pine. The leaves are 

 more rigid, and their axis from the branches is larger." 



