PREFACE. 



This handbook contains descriptions of the seed-plants growing natu- 

 rally in the Miami Limestone Region. This area consists of a chain of lime- 

 stone islands enclosed by the southern portion of the Everglades, except 

 where some of the islands come in contact with the upper half of Bay 

 Biscayne. The chain stretches, in crescent form, from somewhat north of 

 the Miami River southwestward toward Cape Sable for a distance of about 

 fifty-five miles. The islands, apparently, in ancient times formed a part 

 of the Antilles. Their native vegetation is essentially of a tropical char- 

 acter, with strong relationships to the flora of Cuba and of the Bahamas. 

 As far as the native flora is concerned the Everglade Keys represent a 

 small tropical area isolated on the mainland of the United States. 



The vegetation of the islands themselves is divided into two rather 

 distinct plant-associations, namely, pineland and hammock, which are 

 usually sharply differentiated from each other. These in turn are both 

 rather abruptly marked off from the adjacent Everglades. With few 

 exceptions the individual plant-species are distributed generally over the 

 area under consideration. However, they are, in the majority of cases, 

 confined to the one or the other of the plant-associations; consequently, on 

 the following pages the local distribution of the species is indicated as 

 " Pinelands," " Hammocks," " Everglades." 



In addition to the area already described, two minor elements are 

 included in our geographical range, the coastal sand-dunes of the narrow 

 peninsula opposite Miami and also those of Virginia Key and Key Biscayne 

 and the waters of Bay Biscayne itself. 



As the plant-life of the Everglade Keys is closely related to that of 

 the Florida Keys, when a species is common to both, the fact is indicated 

 in this flora by "F. K." (Florida Keys) following the habitat. The 

 relationship of the plant-species of the Miami flora to the flora of the 

 West Indies is also indicated; if a species grows on one or more of the 

 West Indian islands, it is indicated by " Ber." (Bermuda), "Bah." (Ba- 

 hamas), "Cuba" and if it also occurs in other parts of the West Indies 

 it is indicated by "Ant." (Antilles). 



The flowering and fruiting seasons are not indicated ; the plants flower 

 most abundantly in spring and summer, and produce fruit in due time, and 

 although most or essentially all of the rainfall normally occurs from late 

 spring to early fall, the relative high and even temperature of the other 



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