PRELIMINARY REPORT ON PEAT.

CALCAREOUS WATER.
(PLATE 20)
Limestone, whether in the soil or in the water, nearly always has a marked effect on vegetation, many species of plants being peculiar to calcareous habitats, or entirely absent from them, and others much commoner or rarer in such places than elsewhere. In Florida limestone occurs in all sorts of relations to soil and topography, and the opportunities for studying its effects on vegetation are unsurpassed.
This State is noted for its many large limestone springs with beautiful bluish-tinged transparent streams issuing from them. These are numerous in the Gulf hammock region, fairly common in the West Florida limestone region and the lime-sink region of the peninsula, and occasional in several other regions. Some of our calcareous streams have steep banks, and no place for peat to accumulate, but others, especially in the flat Gulf hammock region, are bordered by extensive swamps. The fluctuations of calcareous streams are very much less than those of muddy streams.*
The plants listed below were observed either along Spring Creek (a few miles east of Marianna) in Jackson County, or in or near the Gulf hammock region, or both.
TREES
Taxodium distichum (cypress) Celtis sp. (hackberry)
Acer rubrum (maple) Frazinus Caroliniana? (ash)
Liquidambcr Styraciflua (sweet Fraxinus sp.
gum) Sabal Palmettc (cabbage palmetto)
Magnolia glauca (bay) Quercus Michauxii (swamp chestCarpinus Caroliniana (ironwood) nut oak)
Ulmus Floridana (elm) Pinus Taeda (short-leaf pine)
Quercus nigra (water oak) Juniperus Virginiana (cedar)
SMALL TREES
Ilex Cassine (swamp holly) Salix longipes? (willow)
Viburnum obovatum
*According to U. S. Geol. Surv. Water Supply Paper No. 242, pp. 132-135, the outlet of Silver Spring fluctuated only 1.65 feet during 1907. At a stage a little above the mean it was discharging 608 cubic feet a second. During the same year the Suwannee River at White Springs (where it is essentially non-calcareous) fluctuated 18.9 feet, with a discharge varying from 18 to 816o cubic feet a second.

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