CONIFEROUS FORESTS 



359 



somewhat similar jack pine of the north, it is confined to the most sterile 

 soils imaginable, where other pines are scarce or absent. Its favorite 

 soil, about 99 per cent, white sand, is most extensively developed in the 

 lake region of peninsular Florida, where it supports a peculiar type of 

 vegetation known as " scrub/' consisting mostly of this pine, two small 

 evergreen oaks (Quercus geminata and Q. myrtifolia), saw-palmetto 

 and several other evergreen shrubs, with very little herbaceous growth: 

 grasses and leguminous plants especially being conspicuous by their 



riuitx clausa in '• Scrub," Lake Co., Florida. May, 1909. 



absence. Outside of the lake region this type of soil and vegetation is 

 principally confined to old stationary dunes near the coasts. 



Fire sweeps through the scrub on the average about once in the life- 

 time of the trees, as in the boreal conifer forests, and kills the pines 

 completely; but their cones, which normally remain closed for years, 

 then open and discharge seeds for a new crop. 



The wood of this pine is of little value, and the soil in which it 

 grows is worthless for ordinary crops. But on the east coast of Florida 

 south of latitude 28°, where frost is sufficiently rare to make such 



