274 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
FILLED LAKES, ETC.
PEAT PRAIRIES.
(PLATE 27.)
Whenever a small lake is completely filled with peat it becomes a prairie; and such prairies when dry and firm enough to support a dense growth of broom-sedge do not look very different from old fields, especially in winter and early spring when the water is low and most of the herbage is dead. At such times one can walk across them without much trouble, and it would be hard for a person going into one of these places for the first time to realize that he might be standing on 15 or 20 feet of exceptionally pure peat. The smallest peat prairies are often among the deepest, for they are commonly situated among rather steep hills, whose slopes continue without much change some distance below the surface of the peat. Besides the smaller lakes there are some, especially in Putnam and Polk Counties, which are half a mile or more in diameter and only about half filled with peat, which has essentially the same vegetation on it as that in the completely filled lakes. The difference between the peat prairies bordering the medium-sized lakes of Putnam and Polk Counties and the saw-grass marshes among the large lakes in the central part of the lake region (already described) is probably correlated with the fact that the smaller lakes are strictly noncalcareous, and not connected with streams; while wherever sawgrass grows there seems to be usually a pretty good chance of finding limestone not very far below it.
The following plants have been found in non-calcareous peat prairies in various counties of the lake region.
SMALL TREES
Magnolia glauca (bay) Ilex Cassine (swamp holly)
Persea pubescens (red bay) Gcrdonia Lasianthus (bay)
SHRUBS AND VINES
Smitax laurifolia (bamboo vine) Pieris nitida
Vitis rotundif olia (muscadine) Cholisma ligistrina
Hypericum fasciculatum Cephalanthus occidentalis (button
hlex glabra gallberryy) bush)
Smilax sp. Vaccinium sp. huckleberryy)