128 TIMBER PINES OF THE SOUTHEKN UNITED STATES. 



pines. It is lifjlit, soft, easily worked, and capable of good finish, and is without doubt fit for 

 many uses of the house carpenter and cabinetuiaker in the uiamifacture of furniture and other 

 purposes. Owing to the large percentage of ash and smaller quantity of resinous matter, the 

 actual fuel value of the wood of the Spruce Pine is lower than that of the other Southern pines: 

 for its resinous product the tree is considered of no value, since the resin does not run when it 



is tajiped.' 



In its wood the Spruce Pine resembles Loblolly. The sapwood is wide, and even in trees 

 seventy-five to eighty years old it forms more than three-fourths of all the wood. The change 

 from sap to heart wood begins as early as in the pines mentioned, and as in these is retarded with 

 age and also with aiiy suppression of growth, so that iu stunted young trees the change begins 

 later, and the sapwood of these, as well as old trees, is always composed of a greater number of 

 rings'. While green, the wood is very heavy, weighing 4.5 to 50 pounils per cubic foot, varying iu 

 this respect chiefly with the proportion of sapwood. When kiln-dried, the wood weighs about 27 

 pounds to the cubic foot; it is heavier at the butt, weighing about 31 pounds to the cubic foot, 

 and lightest near the top, where its weight falls as low as 2.5 pounds to the cnhu: foot. As in 

 other pines, the heaviest wood is produced by young trees. The amount of water contained in the 

 fresh wood is quite variable— very great in the sapwood, and consequently iu young timber— but 

 falls little below 50 per cent of the weight of green timber on the whole. Its behavior in drying 

 is the same as in light grades of Loblolly; it dries rapidly and without much injury, shrinking, 

 during this process, by about 10 per cent of its volume. 



The strength of this wood is, as in other conifers, closely related to its weight. Accordingly, 

 the Spruce Pine is inferior to both Shortleaf and Loblolly. 



From careful experiment it appears that its — 



Lbs. jH-r sq. inch. 



Modulus of elasticity is about - 900,000 



Transverse strcngtli •>> *""^ 



Compressiou endwise 4,000 



In its structure the wood resembles too closely that of the Loblolly to enable as yet any 

 identification on this feature, and the description for the wood of the Lol)lolly answers perfectly for 

 the i)r()duct of this species. As in Loblolly and other hard pines, summerwood and spriugwood 

 are always well defined, the summerwood forming from 15 up to 40 per cent of the total volume, 

 differing iu this respect from the White Pine which it has been claimed to resemble. Thus while 

 decidedly softer on the whole than Loblolly it is by no means to be expected that the Spruce Pine 

 can hope to serve as a general substitute for the true White Pine. 



BOTANICAL DESCRIPTION. 



Leaves invariably in ]iairs, with short and close sheath; soft, slender, U to 3 inches long, 

 twisted; cones short-stalked, horizontal or retlexed, the cone scales with a flat apophysis, the 

 depressed umbo unarmed or with a minute weak erect i)rickle. 



The Spruce Pine is readily distinguishe<l by the close bark of its trunk which in the crown and 

 the limbs is perfectly smooth and of a light gray color; in foliage and in cones it resembles most 

 closely the Sand Pine {Pimis clausa) of the coast region of Florida and the eastern (iulf States, 

 which however is distinguished by the more prominent apophysis of the cone scales, armed with a 

 short, stout, reflexed prickle. The Siiortleaf Pine, to which it is next related, is distinguished by 

 the same characters and further by the fascicles of two and three leaves and the rigid young shoots 

 of the season covered with slender, long, loosely fimbriated bud scales. 



The leaves are concave, faintly serrulate, short pointed, and are shed during the latter part 

 of the second season or the beginning of the third. 



In the details of their structure they differ little from the leaves of the Shortleaf Pine; the 

 rows of breathing ])oi-es (stoinata) are numerous on both surfaces; the strengthening cells of the 

 cortical tissue are smaller and less numerous; the resin ducts, two or three, are parenchyma- 

 tous, the cells of the bundle sheath thin walled. The two fibro-vascular bundles distant and 

 without strengthening cells. 



I Ravenel: Proceed, of Elliott Society, Charleston, 1, 52. 



