128 TIMHElt PINES OF Tin; SOUTHEKN UNITED STATES. 



I)ines. It is liglit, soft, easily worked, ami (■ai)abli' ol' jioud liiiish, and is witliout doubt lit for 

 many uses of the house cari>enter aud cabinet makei- in tlie manufacture of furniture and other 

 purposes. Owing to tlie large percentage of ash and snialli'r (piantity of resinous matter, the 

 actual fuel value of the wood of the Sprucre 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 tapped.' 



In its wood the Spruce Pine resembles Loblolly. Tiie 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 ])iiies mentioned, and as in these is retarded with 

 age and also with any snpi)ression of growth, so that iTi 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 {■> to .^O ])onnds jier cubic foot, varying in 

 this respect ehietly with the proportion of sapwood. When kihidried, 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 cubic foot. As in 

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

 IVesh wood is quite variable — very great in the sapwood, and conseciuently in 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 liglit grades of Loblolly; it dries rai>idly and without miudi injury, shrinking 

 during this jjroeess, 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 aud Loblolly. 



From careful experiment it ai>pears that its — 



Lba. i>er sq. im^h. 



Modulus of eliisticity is about 900,000 



Tiaiisverso strength G, 000 



Coiiipression endwise I.OCK) 



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

 identilicatiou ou this feature, aud tlie description for the wood of the Lolilolly answers perfectly for 

 the product of this species. As in Loblolly and other hard ])ines, summerwood and springwood 

 are always well defined, the summerwood forming from 1.") up to 40 per cent of the total V(dume? 

 ditl'eriug in this respect from the White I'ine which it has been claimed to resend)le. 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, li to .3 inches long, 

 twi.sted; cones short-stalked, horizontal or retlexed, tli<! cone scales with a tiat apopiiysis, the 

 depressed uudio unarmed or with a minute weak erect prickle. 



The Spruce Pine is readily distinguished by the close bark of its trunk which in the crown aud 

 the limbs is ])erfectly smooth and of a light gray color; in foliage and in cones it resenildes most 

 closely the Sand Pine {Phius clnnsn) 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, retlexed prickle. The Shortleaf 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 riuid 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 dill'cr little from the leaves of the Shortleaf Pine; tiic 

 rows of breathing pores (stomata) 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. 



' RaTenel: Proceed, of Elliott Society, Charloston, 1, 53. 



