TRANSACTIONS OF WAGNER 



VEGETATION OF SOUTH FLORIDA 



distant. The section which the road makes through the hammock affords 

 unusual advantages to the botanist to study the layers of the forest, the heights 

 of the trees, and their distribution as to light relationship. It also enables one 

 to get vistas of the vegetation and good photographs of individual trees, or 

 associations (Plate V, Fig. 2). The hammock vegetation belongs to the sub- 

 tropic rain forest formation of Schimper.* Everything is new and bewildering 

 to the northern botanist who visits a hammock of this kind for the first time. 

 Two familiar trees, however, form important elements of the dominant growth, 

 where the crown of the trees help to form the canopy above. They are the 

 palmetto, Sabal palmetto (Walt.) R. & S., with tall and columnar stem, their 

 bases covered with a gray moss, Octoblepharum albidum Hedw., and the live- 

 oak, Quercus virginiana L. The palmetto tree was found in young growth in 

 the forest and its leaves contribute materially to the forest litter. Occasionally 

 among its leaf stalks grows a fern, Phlebodium aureum (L.) R. Br. The live-oak 

 is a tree which forms a conspicuous part of the hammock vegetation. It 

 branches freely and its large limbs bend into positions favorable for the most 

 advantageous light exposure of the foliage (Plate V, Fig. 2). Its trunk and 

 branches are loaded with epiphytes, which include the Florida-moss, Tilland- 

 sia usneoides (L.) Raf., that grows in festoons, two bird's nest bromeliads, 

 Tillandsia valenzuelana A. Rich, Tillandsia utriculata L. and two orchids, 

 Beadlea cranichoides (Griseb.) Small, and Epidendrum (Encyclia) tampense 

 (Lindl.) Small. The live-oaks are frequently left when the other trees are 

 cleared away, and in a number of places in the original hammock area near 

 Miami, their form and load of epiphytes may be studied to advantage. The 

 red-mulberry, Morus rubra L., above 20 meters tall, is among the larger trees 

 of this forest, as are also the strangling-fig, Ficus aurea Nutt., F. brevifolia 

 Nutt., and Coccolobis laurifolia Jacq. The strangling-fig, Ficus aurea Nutt., 

 often begins its growth as an epiphyte by fruits carried by birds to the 

 limb of some other forest tree. It sends down aerial roots, which grow about 

 the trunk of the supporting tree, as they grow toward the soil beneath. 

 These roots increase in number until the trunk of the host is surrounded 

 and ultimately strangled. The Scotchman, as it is called locally, then entirely 

 suppresses the other tree, which decays away within the encircling mass 

 of roots, and the fig is left undisputed possessor of the ground and light 

 position. Excellent representations of the Florida strangling-fig made from 

 * Schimper, A. F. W.: Pflanzengeographie auf physiologischer Grundlage, 500-505. 



