TRANSACTIONS OF WAGNER 
I 
34 VEGETATION OF SOUTH FLORIDA 
blends with the pine forest and is transitional to it, when the pines begin to be 
scattered amongst the shrubby oak trees. Hence the oak-saw-palmetto 
sclerophyllous formation stands intermediate between the live-oak hammock 
on the one hand and the pineland on the other. It is probably not a true river 
hammock, but should be included in the category of dry hammocks, but its 
geographic location and its transitional forms have led to its consideration at 
this place. 
Pond Margin Hammock Formation.—Another kind of low hammock in 
South Florida is associated with the margins of the larger and the smaller lakes 
and ponds of the region, and the ecologic character of these different hammocks 
varies as much as the ponds around which they are found. One of the class 
may be taken as illustrative. Near Samville, a few miles north of the Ca- 
loosahatchee River, are a number of almost circular shallow ponds. One of 
these ponds was studied. The margin of the pond with the exception of a low, 
grassy area was fringed with a narrow hammock fronting the pineland on 
the side of the pond. The palmetto, Sabal palmetto (Walt.) R. & S., was the 
most important tree of the border strip. On the west side of the pond, the 
narrow hammock increased in breadth and here the palmetto was associated 
with live-oaks, Quercus virginiana Mill., persimmon, Diospyros virginiana L., 
and buttonbush, Cephalanthus occidentalis L., the trees were festooned with 
the Spanish-moss, Dendropogon (Tillandsia) usneoides (L.) Raf., and connected 
together by the Virginia-creeper, Parthenocissus (Ampelopsis) quinquefolia 
(L.) Planch. The branches of the oak trees supported dense masses of the 
epiphytic fern, Polypodium polypodioides (L.) A. S. Hitchc. (=P. incanum 
Sw.), while the bark of the branches was marked by the red blotches of a 
lichen, Chiodecton sanguineum (Sw.) Wain., mingling with the gray tones of 
another lichen, Parmelia laevigata (Sm.) Nyl. An epiphytic fern, Phlebodium 
aureum (L.) R. Br., previously described, sends its hairy rhizomes in and out 
of the petiole stubs of the palmettos, while the enlarged bases of these trees are 
characterized by three mosses: Bryum Sawyeri Rol., Plagiothecium (Iso- 
pterygium) micans (Sw.) Paris and Octoblepharum albidum Hedw. 
Everglade Hammock Formation.—Finally among low hammocks must be 
included the hammocks that occur in the Everglades. As will be emphasized 
later, the hammocks increase in number in proceeding from Lake Okeechobee 
in a southwestern direction. The Everglades immediately south of the lake 
are practically without tree hammocks, but they increase as we proceed. 
