258 CONIFERS. 



maturing in the autumn of the same year. Scales of the cones thin, not 

 tipped, as in the pine, with a thickened spine. Leaves rigid, foliaceous, 

 scattered, not fasciculate, persistent for two or three years. 



Abies balsam ea Marshall. — Balsam Fir. 



Description. — Cones cylindrical, 2 to 4 inches long, erect on the upper 

 side of the spreading branches; scales mostly deciduous from the persist- 

 ent axis at maturity. Leaves £ to f inch long, narrow, flat, rigid, bright 

 green above, silvery beneath, mostly sessile on horizontal branches, and 

 spreading in two directions so as to seem 2-ranked. 



A slender, tapering tree, rarely more than 40 feet high ; branches dimin- 

 ishing in length in proportion to their height from the ground, forming, 

 under favorable circumstances, a perfectly regular pyramidal head. Bark 

 rather smooth, bearing resin in vesicles. 



Habitat. — In cold damp woods and swamps from New England to Penn- 

 sylvania, Wisconsin, and northward ; common in Canada, not forming for- 

 ests but disseminated among other trees. 



Abies Fraseri Pursh. — Frasers or Southern Balsam Fir. 



Desci^tion. — Cones oblong-ovate, 1 to 2 inches long, otherwise much 

 like the preceding. A small tree. 



Habitat — In the mountains from Pennsylvania to North Carolina. 



Abies Canadensis Michaux. — Hemlock, Hemlock Spruce. 



Description. — Cones oval, \ to f inch long, hanging on the ends of the 

 branches of the preceding year, persistent ; scales not falling away from 

 the axis. Leaves linear, obtuse, \ inch long, scattered, somewhat 2-ranked, 

 dark green above, paler beneath. A large tree, often 70 to 80 feet high, 

 with a diameter of 2 to 3 feet ; in forests, with spreading branches at the 

 top. Bark rough and deeply-furrowed ; wood light, coarse-grained, but 

 comparatively strong, largely used for fences and outbuildings. 



Habitat. — In hilly and rocky soil. In many regions it forms forests of 

 considerable extent, especially on west hillsides. Most common north- 

 ward. It is approaching extinction in . many sections of the Northern 

 United States, since it does not nourish as a second-growth tree. 



Parts Used. — The resinous exudation of all species. That procured 

 from A. balsamea is official under the name Terebinthina Canadensis — 

 Canada turpentine, or Canada balsam. It is contained in blisters or vesi- 

 cles upon the bark and is collected by puncturing these and pressing out 

 their contents. A. Fraseri yields a balsam of identical character. The 

 resinous exudation of A. Canadensis is official under the name Pix Cana- 

 densis — Canada pitch or hemlock pitch. 



Constituents. — Canada turpentine is a yellowish or faintly greenish, 

 transparent, viscid liquid, of an agreeable terebinthinate odor, and a bitter- 

 ish, slightly acrid taste. Exposed to the air it slowly concretes, and forms 

 a mass which is brittle when cold. It is composed of volatile oil and 

 resm. 



