12 BULLETIN UNITED STATES GEOLOGICAL SURVEY. \Vol.Vl. 



.us the Dame of scopulorum {i. c, the Rocky Mountain variety), is 

 the one to which the term "long-leaved" least applies. It is one of the 

 Largest trees of the proper Rocky Mountains, along which it ranges from. 

 latitude 51°, according to \h\ G. M. Dawson, to, New Mexico, is rare on 

 any of the ranges which traverse the Nevada desert, and takes its fullest 

 development and predominance in California and Oregon, extending also 

 into the central dry region of British Columbia. It becomes a large 

 tree even on the interior mountains, in the southern part mostly on slopes 

 between 7,000 and 9,000 feet above the level of the sea, in the most 

 northern ceasing at three to four thousand. Its heavy and coarse- 

 grained I limber is suitable for the ruder building and the mining pur- 

 poses to which it is devoted. 



1*1)1 us contorta, singularly called Tamarack in California, but in British 

 Columbia Bull or Black Pine, and in Utah Red Pine, is also a rather 

 composite species, one of equally great geographical range, but in higher 

 altitudes and latitude than the preceding. It replaces it on the mount- 

 ains of Colorado at between eight or nine and ten or eleven thousand 

 feet : is naturally absent from the Nevada and most of the Utah ranges; 

 in British Columbia, according to young Dr. Dawson, "it is the charac- 

 teristic tree over the northern part of the interior plateau, and densely 

 c< >\ei s great areas. In the southern part of the province it is found only 

 on those parts of the plateau which rise above about 3,500 feet, where 

 the rainfall becomes too- great for the healthy growth of P. ponder om. 

 It grows also abundantly on sandy beaches and river Hats at less ele- 

 vations." Loving moisture and coolness, it is also a coast species even 

 as far south as Mendocino County, California, whence it extends to the 

 Yukon River, in latitude 03°. Northeastward it gets beyond the Rocky 

 Mountains, in latitude 56°, and is replaced by the Banksian Pine "at 

 the watershed between the Athabasca and Saskatchewan." The wood 

 IS white and light (so that the tree is sometimes called Spruce or White 

 Pine), but fairly durable; but the tree never attains a great girth. In 

 London's Encyclopaedia of Trees and Shrubs, where this species is first 

 published on Douglas's specimens, it is named in English "TheTwisted- 

 branched Pine." Douglas is thought to have given the name in refer- 

 ence to the dead and denudated Blender lower brandies, which persist 

 for a long while and curve downward and inward, but do not twist : at 

 least this is the habit of the tree in the mountains. The trunk is per- 

 fectly straight. 



Pinu8aristataoi Engelmann, the only form in our region of the earlier- 

 named P. Balfeuriana of California (from which it differs only in the 

 armed tip of the cone-scales), is well called Fox-tail Pine from the ap- 

 pearance of the leafy branches, on which the closely Bel leaves persist 

 for a dozen years, it belongs only to high mountains and to latitudes 



north of the forty-first parallel, and is nowhere found out of the drier 



districts and their immediate borders. It is a small tree, of only botan- 

 ical interest except in the mountains of Nevada, in the southern part of 



