36 SCIENTIFIC AND APPLIED PHARMACOGNOSY 



GYMNOSPERMS 



This is an ancient group of plants and was especially predominant 

 during the Triassic age. The surviving forms are represented by 

 about 450 species and divided into three classes, viz. : Cycads, Con- 

 iferse and Gnetacese. The most important of these are the Coniferae, 

 which include the two families Taxacese and Pinacese. The latter 

 include about 300 species and are especially abundant in the Northern 

 Temperate regions of the world. They are mostly resinous trees or 

 shrubs and of very great economic importance for timber, ornamental 

 purposes, and they also furnish valuable products which are used 

 in the arts and in medicine. The Pinacese include pine, spruce, hem- 

 lock, fir, larch, the bald-cypress, the redwoods, arbor vitse, and 

 juniper. The Araucarias belonging to the Coniferae resemble in 

 general habit the pine and are the lofty evergreen trees of tropical 

 America and Australia. The Sequoias include the redwood (S. 

 sempervirens) and the big tree (S. gigantea), both natives of California 

 and are among the most massive of any trees in the world, attaining a 

 diameter of 8 meters. They are practically exempt from disease 

 and some are estimated to be nearly 2000 years old. Amber, a 

 valuable fossil resin, is an exudation from trees of the Pinacese, that 

 formerly grew along the shores of the Baltic Sea, especially in East 

 Prussia. 



PINACESE, OR PINE FAMILY 



PINUS ALBA. White Pine Bark. The dried inner bark of 

 Pinus Strobus (Fam. Pinacea?). P. Stobus, commonly known as 

 white pine or Weymouth pine, is the principal timber pine of the 

 northern United States and Canada. The bark contains from 8 

 to 9 per cent of tannin, but is not usually employed for tanning except 

 when other sources of supply are limited. It is collected to a limited 

 extent and is popular in the making of expectorant syrups. After 

 the outer corky layer is removed it is then dried. 



Description. In flat pieces usually not more than 3 dm. in length, 

 nor more than 12 cm. in width and from 1 to 3.5 mm. in thickness; 

 outer surface varying from yellowish-brown to cinnamon-brown and 

 not infrequently with silver-white patches of the inner layer of the 

 periderm and occasional patches of blackish-brown cork, otherwise 

 longitudinally striate with numerous small blisters of oleo-resin cavi- 

 ties and large more or less depressed irregular scars; inner surface 

 yellowish-brown or dark brown and finely striate; fracture tough, 



