competition, disease, or other factors could cause 

 extinction. 



A few more definitions may be repeated from the 

 first report (Little 1975). A rare species has small 

 numbers of individuals throughout its range, which 

 may be restricted or widespread, and may become 

 endangered if environmental conditions become 

 more adverse. The term local species is used here 

 for a species of relatively small range but which is 

 sufficiently common not to be called rare. A species 

 whose range is limited to a particular area, usually 

 small, is cited as endemic. Border or peripheral 

 species reach the limit of their natural range a short 

 distance into the United States, where they may be 

 classed also as rare or local. Of course, these border 

 species could become extinct in the United States 

 and still be common and not endangered in a 

 neighboring country. 



Scientific names (with slight revision) and com- 

 mon names follow the Forest Service Check List 

 (Little 1953). The same definition of a tree is used: a 

 woody plant having one erect perennial stem or 

 trunk at least 3 inches (7.5 centimeters) in diameter 

 at breast height (4Vfe feet or 1.4 meters) a more or 

 less definitely formed crown of foliage, and a height 

 of at least 12 feet (almost 4 meters). 



Previous Work 



Nuttall (1842-49; 1: viii) prepared perhaps the first 

 detailed botanical descriptions, some with colored 

 plates, of the tropical trees of South Florida. He 

 mentioned the large collection of at least 40 tree 

 species from Key West made for the U.S. Army by 

 John Loomis Blodgett (1809-53), local physician. 

 Small, the outstanding authority on the flora of 

 Florida, published much information about the trees 

 of South Florida in books and articles (Small, 1903, 

 1913a, 1913b, 1913c, 1913d, 1933). 



West and Arnold (1946) prepared an illustrated 

 reference on the native trees of Florida. Buswell 

 (1945, 1946) wrote bulletins on the native trees and 

 shrubs of South Florida. Among local lists are the 

 flora of Big Pine Key (Dickson, Woodbury, and Al- 

 exander 1953) and a preliminary checklist of trees of 

 Everglades National Park (Dilley and Craighead 

 1957). Stevenson (1969) has prepared an illustrated 

 list of the native trees and larger shrubs of the 

 Everglades National Park and the Florida Keys and 

 has compiled small maps. 



Long and Lakela (1971) have written a new de- 

 scriptive flora of tropical Florida, following a pre- 

 liminary checklist (Lakela and Craighead 1965). 

 Craighead (1971) has published a first volume on the 

 trees of South Florida. 



Tomlinson (1974) has made a special study of the 

 breeding mechanisms in the trees and shrubs of 

 southern Florida south of Lake Okeechobee, plus 

 coastal strips on each side whose limits correspond 

 to 50° F. January isotherm. In this region, which 

 was called tropical Florida, he listed 114 species of 

 woody plants, 98 of them tropical. 



This Compilation 



The basis of this report is the compilation of dis- 

 tribution maps showing the natural range of each 

 tree species for the "Atlas of United States Trees" 

 (Little 1971). A separate volume for the native trees 

 of Florida is in preparation. Preliminary maps have 

 been compiled mainly from specimens and unpub- 

 lished maps in the herbaria of four universities: Uni- 

 versity of South Florida, University of Miami, Uni- 

 versity of Florida, and Florida State University. 

 Credit is due the staffs of these herbaria for permis- 

 sion to use these basic records and for assistance. 

 Records have been compliled also from publications, 

 especially floras, local floras, and tree books. Addi- 

 tional information on tree distribution was contrib- 

 uted by George N. Avery, Frank C. Craighead, Sr., 

 William T. Gillis, and Roy 0. Woodbury. 



According to the distribution maps, about 100 

 species of native trees are confined to South Florida 

 and may be classed as tropical. These are found 

 mostly in the southern third of the State, the penin- 

 sula from Lake Okeechobee southward. Some ex- 

 tend northward along the coasts in the central part 

 to Cape Kennedy or beyond on the east coast and to 

 Tampa Bay or even Cedar Key on the west. 



Of the native tropical tree species in South 

 Florida, more than one-third have a relatively broad 

 distribution in several counties and are not classed 

 as rare. These trees apparently are hardy and toler- 

 ant of winter temperatures several degrees below 

 freezing. Some are common locally, and most are 

 protected somewhere within parks, natural areas, 

 or other preserves. The 41 tropical tree species na- 

 tive in South Florida but omitted here as not rare are 

 listed in the appendix. 



The rare tropical trees of South Florida are to be 

 sought among the species restricted to the three 

 southernmost counties, Dade, Monroe, and Collier, 

 and especially those confined to the chain of islands 

 mostly in Monroe County extending southwestward 

 to Key West and known as the Florida Keys. These 

 islands are further divided from north to south into 

 the Upper Keys and Lower Keys. (The similar term 

 Everglade Keys is applied to limestone ridges in the 

 Everglades region on the mainland in southern Dade 

 County and partly within Everglades National 

 Park.)' 



