FREE INSTITUTE OF SCIENCE 



VEGETATION OF SOUTH FLORIDA 



Cenchrus carolinianus L. 



o Galactia spiciformis T. & G. 



Chamaesyce Blodgetii (Engelm.) Small. 



o Mimusops Sieberi A. DC. 



== Solarium Blodgetii Chapm. 



Ximenia americana L. 

 + Ageratum littorale A. Gray. 



LOW HAMMOCK FORMATIONS 



The low hammocks are characterized by a wetter soil than the high ham- 

 mocks and are found along streams, lakes, in the Everglades, along wet prairies, 

 cypress swamps, tree and bush swamps and marshes. Three main kinds were 

 studied by the writer, namely, river hammocks, pond hammocks and Everglade 

 hammocks. 



River Hammock Formation. Although this formation is considered in the 

 collective sense as including all hammock vegetation along river or stream 

 banks, yet, strictly speaking, we can distinguish several kinds of river ham- 

 mocks, such as live-oak hammocks, palmetto hammocks, or mixed tree ham- 

 mocks. In South Florida, its river hammocks form an important part of the 

 vegetation. They exist either as narrow strips paralleling the banks of 

 the rivers, or they occupy ox-bow-like bends of the river bank, or form large 

 areas many acres in extent. They were seen and in some places studied along 

 the Miami, Little, New, and Caloosahatchee rivers (Plate VI, Figs, i and 2). 



Along the Miami River, true hammock vegetation appears above the fork 

 of the stream, especially in undisturbed condition on the South Fork. Here one 

 notes as the constituent trees and shrubs, Chrysobalanus pellocarpus G. F. W. 

 Mey., Erythrina arborea (Chapm.) Small, Citrus limetta Risso, gumbo-limbo, 

 Elaphrium simaruba (L.) Rose, Ilex cassine L., Persea (Tamala) pubescens 

 (Pursh) Sarg., Icacorea paniculata (Nutt.) Sudw., Psychotria undata Jacq. 

 In one place at a bend of the stream, a hammock grove of live-oak trees was 

 noted. These oaks were 15 meters (50 feet) tall with numerous twisted 

 branches and gray bark. The branches were loaded with epiphytes. One 

 species of Tillandsia, probably T. utriculata L., was a huge plant with its flat, 

 dilated leaf bases overlapping to form a deep, basin-like hollow filled with 

 water out of which the branched inflorescence arose. The Florida-moss, 

 Tillandsia (Dendropogon) usneoides (L.) Raf., festooned the oak trees with long, 



