386 CLASS XXI. ORDER IX. 



ed ; cones cylindric, erect; scales obovate, mucronate, 



serrulate. 



Syn. Abies balsamifera. Mx. 



The Silver Fir is a small tree, forty or fifty feet high, much 

 cultivated for its beauty, but not very valuable for its wood. 

 The branches are clothed with lateral leaves, which exceed ia 

 length those of the species which follow, and appear whitish un- 

 derneath. Cones large, erect, bluish. — In Maine and New 

 Hampshire, common. 



PiNus NIGRA. Ait. Black or double Spruce. 



Leaves solitary, four cornered, erect, straight; 

 cones ovate, scales elliptical, waved at the edge, 

 erect. Lamb. 

 Syn. Abies nigra. Mich. 



The branches of the double Spruce are thickly covered on all 

 sides with short, dark colored, linear leaves, inserted laterally 

 and singly. The cones are small, oval, pendulous, composed of 

 thin scales, which are waved and crenate, or partially cleft on 

 the edge. 



This tree is not very common, unless cultivated, in the envi- 

 rons of Boston. At the eastward it is frequent. Its wood is 

 light, strong, and elastic, and much used for the smaller spars of 

 vessels. 



PiNus alba. Ait. White or single Spruce, 



Leaves solitary, four sided, incurved; cones sub- 



cylindric, lax; scales obovate, entire. 



Syn. Abies alba. Mx. 

 A smaller tree than the black Spruce, and its wood deemed 



inferior. — Principally found in the parts of New England east of 



Boston. 



PiNus Canadensis. L. Hemlock Spruce. 



Leaves solitary, flat, denticulate, nearly in two 

 rows; cones ovate, terminal, hardly longer than the 

 leaves. Lamb. 



