138 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT. 
such places differ greatly in their vegetation from those where there 
is nothing to check the spread of fire. It would be hard to find an 
area of the same size which affords better opportunities for studying 
the effects of different frequencies of fire than this one does. 
In the lists of plants both technical and common names are given 
when possible. The technical names correspond for the most part 
with those in Small’s Flora of the Southeastern United States, 
though that encyclopedic work is not followed in any case where it 
is known to be incorrect or out of date. Nearly all the trees have 
common names, but some of the smaller plants of course are so in¬ 
conspicuous or unimportant that they have never been named except 
by botanists. For many such plants alleged common names can in¬ 
deed bei found in botanical books, but they would mean no more to 
the average reader than the technical names do. The common 
names adopted here are bona-fide ones, known to be used in Florida 
by persons without botanical training; but in a few cases names used 
in other states, which may be familiar to some readers, are given in 
parentheses. 
The technical names of evergreens are printed in heavy type, and 
in the case of semi-evergreens only the second half of the name is 
thus printed. This will help the reader to picture to himself the winter 
aspects of the vegetation, and the contrasts between different types. 
The significance of evergreens is more than merely ornamental, too, 
for it is pretty evident to an intelligent observer that, in the eastern 
United States at least, they are most abundant in the poorer soils, 
and vice versa. Within the area here treated the proportion of ever¬ 
green trees in different types of forest varies from less than 10% 
to over 90% ; and those which have over 90% are rarely disturbed 
• by the farmer.* 
It is interesting to consider also the proportion in each vegeta¬ 
tion type of plants belonging to certain well known and widely dis¬ 
tributed families, such as the Ericaceae and allied families (heaths, 
huckleberries, etc)., Leguminosae (leguminous plants) and Grami- 
neae (grasses). The Ericaceae are especially characteristic of sour 
soils, poor in lime or potash, or both, and the Leguminosae of upland 
soils pretty well supplied with mineral plant food but poor in humus 
% (for they have a way of getting nitrogen from the air, without hav- 
*For a discussion of the relation of evergreens to soils see 6th Annual 
Report, pp. 175-177 (footnote), 396. 
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