Pinus 1 049 



branchlets reddish brown, with a scattered minute stiff pubescence. Leaves similar 

 to those of P. flexilis, persisting five to eight years. 



Cones sub- terminal, sessile, spreading, never opening, ovoid, i|^ to 3 in. long, 

 dark purple when growing, light brown when mature ; scales much thickened, very 

 brittle at their base, f in. long, f in. broad, many undeveloped and unfertile ; 

 apophysis triangular, ending in a sharp-pointed umbo. Seed, ^ to ^ in. long, ovoid, 

 more or less compressed, pointed at the apex, pubescent ; wing rudimentary or 

 absent. 



In the absence of cones, this species is best distinguished from P. flexilis by the 

 minute scattered stiff hairs on the reddish brown branchlets. The young branchlets 

 of P. flexilis are either quite glabrous or covered with a soft fine tomentum. 



This species is more alpine in distribution than P. flexilis, forming the 

 timber line on many mountain ranges from lat. 53° in Alberta and British 

 Columbia,^ southward along the Rocky Mountains to the Yellowstone plateau, 

 and through Washington and Oregon in the Cascade and Blue mountains, and 

 in California, along the Sierra Nevada to the San Bernardino mountains. It 

 reaches an elevation of 5000 ft. in the north, and 1 2,000 ft. in the south. This species ^ 

 endures great seasonal ranges of temperature from —60° to 100° Fahr. ; severe winds 

 and a very short growing season being characteristic of its habitat. It is probably 

 the least exacting of all conifers as regards both soil and moisture — the annual precipita- 

 tion, a large proportion of it in the form of snow, sometimes being as little as 1 5 in. 



In north-western Montana this species^ does not cross the continental divide, 

 and grows at elevations between 6000 and 8000 ft., usually in scattered groves, 

 either pure or mixed with Picea Engelmanni and Abies lasiocarpa. It is often seen 

 on high exposed ridges, and strongly resembles P. Cembra in general appearance, 

 being often irregularly branched and with a flattened crown of foliage. The largest 

 tree (Plate 276) measured by me on Mount Nicholas, and photographed by Prof. 

 Elrod, was 84 ft. high and 9 ft. 2 in. in girth. 



Sir Joseph Hooker describes and figures* this tree on Mount Shasta, where the 

 trunk becomes scored and polished by the sand blasts. Elwes saw it here in 1904 

 at about 7000 to 8000 feet elevation. 



The most remarkable feature of this pine, in which it resembles P. Cembra, is 

 that the cones never open, the seeds being distributed by squirrels, who readily 

 break off the scales, which are very brittle towards the base. 



P. albicaulis was discovered ^ on the mountains rising above the valley of the 

 lower Fraser river, near Fort Hope, in 1851 by John Jeffrey, who sent seeds 

 from Mount Shasta, California, in 1852, to Scotland, from which a few plants were 

 raised, but none of these appear to have survived. The only specimens we know m 

 cultivation are seedlings at Kew about 6 in. high. 



The timber when accessible is used by miners for props, fuel, and sleepers. 



(A. H.) 



1 Dawson, in Canad. Naturalist, ix. 328 (1881) says : " In the coast or Cascade ranges as far north as the Iltasyouco river 



^''*" fSuS SyMcal Leaflet 37, White Bark Pine (1908). 3 jt occurs also in the Helena National Forest in Montana. 



* Card. Chron. xxiv. 9, fig. 2 (1885). ^ Sargent, Silva N, A,ner. x>. 41 (i897). ^ 



V 



