TSUGA 269 



A small tree 12-15 m - high, with a trunk .60-. 75 m. in diameter. 

 Wood light, soft, not strong, brittle, coarse grained. 



Relative specific gravity 0.4275 



Percentage of ash residue 0.40 



Approximate relative fuel value 42.58 



Coefficient of elasticity in kilograms on millimeters . . 713. 



Ultimate transverse strength in kilograms 10,7. 



Ultimate resistance to longitudinal crushing in kilograms 6450. 



Resistance to indentation to 1.27 mm. in kilograms . . 1996. 

 (Sargent) 



Dry, rocky ridges ; rare and local at elevations of 4000-5000 feet. 



Southern Allegheny region ; Bluff Mountain, Pinnacle Mountain, New 

 River, Whitesides Mountain, and Devil's Court-House Peak, North Caro- 

 lina ; Saluda Mountain, Caesar's Head, South Carolina (Sargent). 



4. T. Pattoniana, Se'nec. 



Mountain Hemlock. Pattern Spruce 



Transverse. Growth rings variable, chiefly rather narrow, the structure 

 usually open throughout. Summer wood very narrow, rather open, 

 the transition from the spring wood very gradual. Spring tracheids 

 rather large and thin-walled, conspicuously squarish, uniform, in 

 regular rows. Medullary rays numerous, broad, i cell wide, rather 

 prominent, distant 2-7 rows of tracheids. Resin passages sometimes 

 present though imperfectly formed, generally in a short zone on the 

 outer face of widely distant growth rings. Resin cells on the outer 

 face of the summer wood numerous, resinous, and prominent, some- 

 times aggregated to form distinct and rather broad zones. Resinous 

 tracheids often forming small groups or radial series in contact with 

 the rays. 



Radial. Rays uniformly somewhat resinous throughout ; the ray tracheids 

 narrow, marginal, often locally wanting. Ray cells straight or some- 

 what contracted at the ends, equal to 10-15 spring tracheids; the 

 terminal walls sparingly pitted ; the upper and lower walls medium to 

 thick, rather strongly pitted, especially in the summer wood ; the 

 lateral walls with small, oval, at first narrowly bordered pits, the len- 

 ticular orifice at length oblong, 1-4, chiefly 2, per tracheid, becoming 

 i in the summer wood, where the orifice is a prolonged slit. Bordered 

 pits round or elliptical, chiefly somewhat distant in i row, large, 

 the round orifice large. Pits on the tangential walls of the summer 

 wood not very numerous, small, often remote and obscure. Resin 

 cells on the outer face of the summer wood 15-20 p. wide, 115-275 //, 

 long, chiefly about 150 p.. Resinous tracheids sometimes locally 

 numerous, the resin massive. 



Tangential. Rays numerous, medium to high, somewhat resinous ; the cells 

 oblong-oval, more rarely oval, rather equal and uniform. Ray tra- 

 cheids very few, terminal, very often wanting. 



