TRANSACTIONS OF WAGNER 



VEGETATION OF SOUTH FLORIDA 



virens L. and Chamsecrista brachiata Pol. enliven the dunes with the color of 

 their flowers. 



The low elevation above the upper beach at Fairyland, opposite Miami, 

 may be termed a dune for want of a better name, but here it has been changed 

 greatly by the planting of a row of tall cocoanut trees, Cocos nucifera L. The 

 dune complex consists of a flat, slightly undulated surface of quartz sand, 

 which extends clear across the peninsula to the edge of the mangrove forma- 

 tion which fringes the shore of the Bay Biscayne. The low trees, shrubs, and 

 herbs of this area are in places widely spaced with sandy hollows and flat 

 sandy intervals between the plants, while in other places the shrubs close to- 

 gether to form a low thicket. 



Low, rounded palms, Serenoa serrulata (Michx.) Hook., are either isolated 

 or they are found forming a tangled covering to hillocks of sand. The saw- 

 palmetto frequently is found in the form with silvered, or glaucous leaves as 

 well as the form with bright-green leaves. Another common shrub of the 

 dune complex with plum-like, edible fruit is the cocoa-plum, Chrysobalanus 

 icacoL. The seaside-grape, Coccolobis uvifera (L.) Jacq., forms low, widely 

 spreading growths and is conspicuous with its broad, clasping leaves. The so- 

 called sagebrush, Lantana involucrata L., with its showy flowers, is strongly 

 redolent at times, especially when its leaves are crushed. As a growth form 

 it suggests the shrubby species of Ceanothus common in the California chap- 

 arral, and ecologically, Lantana replaces Ceanothus on the dry dunes of South 

 Florida. Croton punctatus Jacq. may be classified similarly from the stand- 

 point of ecologic habitat. Two mimosaceous shrubs form part of the con- 

 spicuous growth of this dune complex. They are the unarmed shrub, called 

 cat's-claw, Pithecolobium unguis-cati (L.) Benth., and the spiny blackbead, 

 P. guadalupensis Chapm., that suggest the scrub of the Bahamas of which 

 they are elements. The poisonous doctor-gum, Rhus toxiferum L. [ = Meto- 

 pium toxiferum (L.) Krug and Urban], is occasional as an element of the sandy 

 strand vegetation, as also the unarmed shrub with pale bark, known as the 

 seven-year apple, Genipa (Casasia) clusiaefolia (Jacq.) Griseb. Two rubiaceous 

 shrubs, Erithalis fructicosa L. and Ernodea littoralis Sw., are noteworthy be- 

 cause they are covered by that curious climbing yellow and green vine with 

 matted stems, Cassytha filiformis L., which much resembles the dodder. The 

 leaves are scale-like, and the greenish-white flowers are hi short spikes.* 



* Cf . Boewig, Harriet: The Histology and Development of Cassytha filiformis L. Contributions 

 rom the Bot. Lab., Univ. of Pa., Vol. II, 399-416, 1904. 



