330 FLORIDA GEOLOGICAL SURVEY SIXTH ANNUAL REPORT. 



ble for being a tidal estuary all the way through this region, a dis- 

 tance of nearly loo miles. 



Shallow ponds and bays a few acres in extent, which dry up in 

 spring, are frequent throughout, and west of Trail Ridge there are 

 several large shallow lakes,* The ground- water is nearly every- 

 where close enough to the surface to be easily raised by suction 

 pumps. Old-fashioned "well-sweeps" can still be seen in a few 

 places. Artesian wells are common, and furnish good water in 

 abundance, which rises above the surface nearly everywhere east of 

 the low ridge or terrace above mentioned. 



Vegetation Types — Open forests of long-leaf pine, with an un- 

 dergrowth of saw-palmetto, gallberry, wire-grass, etc., and bearing 

 the marks of frequent fires, are the dominant feature of the land- 

 scape. On the highest and driest spots the blackvjack oak is a con- 

 spicuous feature, as in the high pine land of several other regions. 

 The streams are all bordered by swamps or hammocks, or both. 

 The shallow ponds are all full of trees, either black gum, cypress, 

 slash pine, or bay vegetati'on predominating, according to the na- 

 ture of the soil and the amount of seasonal fluctuation of the water. 

 Treeless marshes occur in some places along the St. John's River 

 and its tributaries, passing gradually into the brackish marshes of 

 the coast. The vegetation of marly spots, referred to above, is much 

 like that of the low hammocks of the Gulf hammock region. A few 

 miles back from the coast in St. John's County there are a few areas 

 of scrub vegetation, probably indicating old dunes. 



Plants — In order to bring out certain differences, as well as 

 similarities, between the western and eastern halves of the region the 

 percentages have been computed separately for the portions on op- 

 posite sides of Trail Ridge. The first column of figures is for the 

 western division and the other for the eastern. Field work in the 

 western portion has been done on 30 different days, distributed 

 through the year as follows : January, 3 ; February, i ; March, i ; 

 April, 2; May, 8; July, 11 ; August, 2; December, 2. The eastern 

 portion has been explored on 21 different days, as follows: Janu- 

 ary, 3 ; February, i ; March, 2 ; May, 8 ; July, 2 ; August, i ; Decem- 

 ber, 4. As I have no notes for either portion between the first week 

 in August and the second week in December no doubt many of the 

 fall-blooming herbs do not figure as largely in the following list 



"See 3d Ann. Rep., p. 272. 



