TRANSACTIONS OF WAGNER 

 '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. 



