354 General Botany 



shortleaf pine, cypress, white cedar, and gum. Cypress is an 

 especially valuable wood for use in building greenhouses, for 

 it withstands without decay warm and moist conditions. 



The southeastern conifer forest region has also been the center 

 of production of turpentine and rosin, which are obtained from 

 the longleaf yellow pine. A V-shaped cut is made through the 

 sapwood of these big trees ; the resin from the wood flows out 

 slowly and collects in a large cup placed at the lower end of the V. 

 The cups are allowed to remain for several months and then 

 the accumulated resin is collected and distilled. The volatile 

 oil, turpentine, passes over into a condenser and the rosin is left 

 behind in the retort. The trees are tapped for three or four years 

 and then cut for timber. The annual output amounts to more 

 than 29 million gallons of turpentine and 3 million barrels of rosin. 



Next to oak, the yellow pine is the biggest source of railroad 

 ties. It is also used for poles and fence posts and for soft-wood 

 distillation. The products of distillation in this case are char- 

 coal, turpentine, pitch, and tar. Red gum is the principal wood 

 used in the manufacture of cheap barrel staves, and pine is used 

 for barrel heads. Arkansas is the leading state in the produc- 

 tion of " slack " cooperage, and in the production of red gum, 

 yellow pine, and cottonwood veneers, now so extensively used 

 in packing crates, door panels, drawer bottoms, and chair seats. 

 Sumac leaves are gathered in large quantities in the southern 

 coastal plain, dried, ground up, and used as one of the sources of 

 tannin. About a fifth of the paper pulp now comes from the 

 southern yellow pine, gum, and cottonwood. Osage orange wood 

 is a promising source of dyes for wool, leather, wood, and paper ; the 

 shades of these dyes varies from orange-yellow to olive and brown. 



The greatest crop plant of the southeastern forest region is 

 cotton. This plant belongs to the mallow family and is a native 

 of the tropics. It requires high temperatures and can be grown 

 only where the frostless season exceeds 6 months. Cotton lint 

 is made up of the hairs that thickly surround the cotton seeds ; 



