PINACE^ 427 



large, non-resinous, c^^lindrical, pointed, l},'2 in. long, with lance- 

 shaped silvery white scales which are ciliate and reflexed at the 

 apex, and persist as a sheath of bud scales at the apex of the second 

 year's branchlet. Leaves in threes, lasting two years, densely 

 crowded on the branchlet, slender, flexible, up to 18 in. long on 

 young, vigorous trees, and about 9 in. long on old trees, margins 

 minutely toothed, apex pointed, stomatic lines on each surface ; 

 resin canals median ; basal sheath |-1 in. long. Cones sub- 

 terminal, spreading, cylindrical or oblong-conic, 6-10 in. long, 

 2-3 in. broad, dull nut-brown, leaving a few scales attached to 

 the branchlet when falling ; scales thin, flat, 2 in. long, | in. wide, 

 the terminal portion rhomboidal and transversely keeled with a 

 reflexed prickle. Seed about |- in. long, with a wing three times 

 its length. 



P. palustris is very distinct in its large white, fringed bud and 

 elongated cone. 



Native of E.N. America, where it forms forests many miles 

 in width along the Atlantic and GuK States from Virginia to 

 Florida. Introduced to the British Isles in 1730, but a failure 

 in this country owing to its tender constitution. 



Wood very hard, strong, tough, and resinous, with numerous 

 and conspicuous resin-ducts. Heartwood light red or orange, 

 sapwood lighter, annual rings very prominent. The timber is 

 more highly esteemed than that of any other pine for heavy 

 constructive work, both for strength and durability, and it is 

 usually regarded as the standard of comparison for other soft 

 woods. In discussing the wood Roth says : ^ " In its stiffness 

 and strength the wood is remarkable. The average of a great 

 number of tests indicates for the dry wood of long-leaf pine an 

 elasticity of 1,540,000 lb. per square inch ; strength in cross- 

 breaking, 10,900 lb. per square in. ; strength in compression, 

 6,850 lb. per square in. ; strength in tension, 15,200 lb. per 

 square in. ; strength in shearing, 706 lb. per square in." 



It grows with three other species, P. caribcea, P. Tceda, and 

 P. mitis, and the timber of the four trees is often mixed in com- 

 merce. P. carihcea is as strong, and in tests has sometimes been 

 found to exceed in strength the wood of P. palustris. The timber 

 of both P. Tceda and P. mitis are however much inferior both in 

 strength and durability. The wood of these four species is so 

 similar even in microscopic characters that it is practically impos- 

 sible to separate them, and the mixing of the timber goes on 

 unchecked. Even in strength tests a good grade of P. Tceda 

 or P. mitis may prove superior to an inferior log of P. palustris. 

 The wood has a world-wide reputation, and in the British Isles 

 it is known almost exclusively as pitch pine, although in America 

 it is commonly known as yellow or long-leaf pine. It is used for 



1 Molir and Roth, The Timber Pines of the Southern United States, 53 (1897). 



