204 FLORIDA GEOLOGICAL SURVEY I3TH ANNUAL REPORT 



from railroads, but the boundary between them and the pine forests 

 is said to be pretty sharp, and they are said to have some pretty fer- 

 tile spots, and more abundant animal life (both wild and domesti- 

 cated) than most of our prairies. 



This type of prairie is subject to fire practically every year, 

 like the flatwoods. Its chief economic importance is as pasturage 

 for vast herds of cattle. 



SHRUBBY VEGETATION ^. 



Sazv-palmetto thickets (fig. 33). The outer dunes of the east 

 coast in the latitude of Melbourne are covered with an almost im- 

 penetrable growth of saw-palmetto about waist-high, with perhaps 

 1% of other shrubs* of about the same height, principally a small 

 oak, Quercus myrtifolia. The palmetto leaves in such situations, in- 

 stead of being yellowish green as in the interior of the State, are 

 covered with a thin gray waxy coating, making a strong contrast 

 with the bright green oak leaves. (This color phase of the palmetto 

 is common within a few miles of the coast, the green type gradually 

 replacing it farther inland, without any apparent intergradation.) 

 Just why trees are absent there is not certain, but the strong wind 

 probably has something to do with it. Fire must be a rare occur- 

 rence; and neither the vegetation nor the soil on which it grows 

 seems to be utilized for anything at present. 



Some of the treeless areas described on the preceding page might 

 be classed as palmetto thickets instead of prairies, where the growth 

 of palmetto is dense, but the other species associated with it would 

 of course be mostly different from those on the dunes. 



Scrub thickets. This term is used to cover various thickets 

 of shrubs no higher than a man's head, widely scattered over our 

 area, but usually of very limited extent. Those on the peninsulas 

 of Lake Tsala Apopka were described and figured in the Seventh 

 Annual Report (pp. 141-142, 155). Other thickets that may come 

 under this head are found near the mouth of the beautiful Pithla- 

 chascootee River in Pasco County. Wherever typical scrub (de- 

 scribed farther on) occurs there may be areas in it devoid of trees, 



*The palmetto is not a shrub, strictly speaking, but its stiff evergreen 

 leaves occupy about the same position that the branches of ordinary shrubs 

 do. 



