PlNE TREES OF ROCKY MOUNTAIN REGION. 7 



LIMBER PINE. 



v Pinus flexilis James! 



COMMON NAME AND EARLY HISTORY. 



Pinus flexilis is generally known in its mountain habitat as " white 

 pine"; but as this name properly belongs to Pinus strobus of north- 

 eastern United States, the common name " limber pine," coined from 

 the tree's technical name, flexilis, has been adopted. This name ap- 

 propriately refers to the marked flexible quality of the twigs. 



Limber pine was found first in 1820 near timber-line at the base of 

 Pike's Peak, Colo., by Dr. Edwin James, a United States Army 

 surgeon and naturalist attached to Stephen Harriman Long's expedi- 

 tion to the Rocky Mountains. Dr. James was also the first to name 

 and describe this tree, his account of it being published in 1823. 

 Since that time the botanical history of limber pine has been moder- 

 ately free from confusion with related white pines of its range. 1 



DISTINGUISHING CHARACTERISTICS. 



Pinus flexilis is a comparatively little-known species, doubtless 

 because it grows chiefly in high places difficult of access. It is a low, 

 thick-trunked, much-branched tree, from 25 to 50 feet in height, or 

 sometimes 80 feet, with a short trunk from 12 to 30 inches in diam- 

 eter; occasionally very old trees are from 3^ to 4 feet in diameter. 

 Young trees are peculiar for their regular distinct whorls of short, 

 very tough branches, which stand out at right angles to the trunk 

 and extend down to the ground. Middle-aged and old trees (from 

 75 to 200 years old) are characterized by extremely long and slender 

 branches, especially near the ground and at the top; the latter are 

 often 16 or 18 feet long and droop gracefully at a sharp angle with 

 the trunk. These branches appear to develop entirely at the expense 

 of the trunk, which remains stunted. 



Large trunks have blackish or very dark-brown bark, which is 

 from \\ to nearly 2 inches thick and deeply furrowed between the 

 wide rectangular blocks ; on trunks from 8 to 12 inches thick the bark 

 is broken into small, thin, gray-brown plates. When separated, the 

 scales expose a dull reddish inner bark. The thin, smooth bark of 

 young pole-size trees and of branches is a bright whitish- gray, often 



1 Dr. C. C. Parry is said to have been the first to introduce this pine into cultivation, 

 plants having been raised in the Harvard Botanic Garden from seed he collected in Colo- 

 rado in 1861. The tree is possibly not adapted to our eastern climate, for the trees 

 raised from Dr. Parry's seed attained a height of only about 5 feet in 35 years. Further 

 planting of the tree at the Letchworth Park Forest and Arboretum, Wyoming County, 

 N. Y., will later throw light upon this question. It appears to be better adapted to the 

 climate of England, where, according to Elwes and Henry (The Trees of Great Britain 

 and Ireland, V, 1048, 1910), three trees in Kew Gardens, probably grown from Dr. 

 Parry's seed, had reached a height of 32 feet and about 11 inches in diameter in 1910. 

 Other smaller trees planted in England are growing thriftily. 



