GYMNOSPERMS 



15 



scales tipped with a short, abruptly curved spine. Wood hard, 

 coarse and resinous, mainly used for fuel. Poor, sandy soil, 

 especially eastward. 



FIG. 1. Scotch Pine (P. sylvestris). 



1, a twig showing : a, staminate catkins ; b, pistillate catkins ; c, a cone ; d, needles. 

 2, an anther, a, side view ; b, outer surface. 3, a carpel-scale, a, inner surface ; 

 b, outer surface. 4, a cone-scale, a seed-wing, and a seed. 5, section of a seed, 

 showing the embryo. (1) is natural size ; the other parts of the figure are magni- 

 fied by the amount indicated by comparison with the vertical line alongside each. 



4. P. inops, Ait. SCRUB PINE. A small tree, usually 20-30 ft. 

 high, but sometimes much taller ; bark of the trunk rough, nearly 

 black; twigs smooth and with a bloom. Leaves in twos, 1-2 in. 



