l8. PENINSULAR LAKE REGION. 32I 



offered. Lime-sinks, caves and natural bridges are unknown, and 

 sprnigs rare. 



The ground-water level is generally nearer the surface and 

 more constant here than in the lime-sink region. Nearly all the de- 

 pressions contain beautiful lakes, averaging at least one to the 

 square mile, and ranging in size from an acre to several square 

 miles. Lakes only a short distance apart sometimes differ consider- 

 ably in elevation, showing that the ground-water surface is irregu- 

 lar, probably conforming approximately with that of the clay sub- 

 stratum. Some of the smallest lakes have become filled with peat, 

 and some of the larger ones show plainly the effects of wave action 

 on their shores. Some of the lakes have remarkably clear water, but 

 in most of them, as in the few streams, it is tinged brown from 

 vegetable matter, though practically free from lime or mud. 



Vegetation Types — The uplands are covered mostly with high 

 pine land vegetation, subject to fire every year or two, much like 

 that of the lime-sink region. A very different upland type of vege- 

 tation, in northern Florida almost confined to the lake region, is 

 known as scrub. This is almost wholly evergreen, and practically 

 devoid of grasses and Leguminosae. Both in the lake region and 

 elsewhere this sort of vegetation occurs almost always on white sand 

 with very little animal life in it. Fire sweeps through the scrub on 

 the average about once in the average life-time of the dominant tree 

 (Pinus clausa), and kills the pines, but they soon come up again 

 from seed. 



The more level areas, or flatwoods, have low pine land vegeta- 

 tion not very different from that in some of the other regions. In 

 the flatwoods near the Ocklawaha River there are places where the 

 vegetation seems to indicate marl near the surface, both in the fire- 

 swept pine forests and in shady low hammocks something like those 

 in the Gulf hammock region. Sandy hammocks, or high hammocks, 

 occur near some of the streams and lakes, especially on peninsulas. 

 The streams and lakes are bordered in many places by non-alluvial 

 swamp vegetation, and there are quite a number of peat prairies or 

 marslies, like those described in the Third Annual Report (pp. 274- 



2/5)- 



Plants — The following list is based on observations made on 3 



days in January, 5 in May, 2 in July and i in December; only 1 1 in 

 all. It therefore cannot be considered very complete, especially for 

 fall flowers, and some of the percentages for herbs may not be very 

 accurate. 



