Occurrence in the Virfjin Islands is cited in the 

 followin<r order: St. Croix, St. Thomas, St. Jolm, 

 Tortola, \"ir^iii (iorda, and Ane<iada. The first 

 three are the United States Virgin Ishmds, while 

 tile last three as well as several smaller compose 

 the British Virgin Islands. 



Witliin Puerto Rico the distribution is recorded 

 in greater detail by notes on abundance, altitudinal 

 limits, and habitat or site. For many sjiecies are 

 mentioned the forest regions or environments, or 

 ecological regions or provinces. The natural dis- 

 tribution of most native trees tends to be related 

 to ecological regions defined by climate and soil. 

 These eight regions, shown in figure 2, define cli- 

 max forests of distinct types. They are described 

 in detail under Forests and Forestry (p. 12) . 



Public Forests 



The public forests in Puerto Rico under Federal 

 and Commonwealth administration, shown in fig- 

 ure o, are widely distributed over the island and 

 contain examples of most common tree species. 

 These forests are accessible by highways or roads, 

 and the personnel in charge can assist in locating 

 and identifying the common trees. 



Occurrence of native tree species in the 15 public 

 forests is summarized by alphabetical lists which 

 indicate localities where examples can be found. 

 Luquillo Experimental Forest, formerly the Car- 

 ibbean National Forest, is administered by the 

 United States Forest Service. The following 14 

 public forests are under the Commonwealth Divi- 

 sion of Forests, Fisheries, and Wildlife : Aguirre, 

 Boqueron, Cambalache Experimental Forest, 

 Carite, Ceiba, (luajataca, Giianica, Guilarte, 

 Maricao, Rio Abajo, San Juan, Susua, Toro 

 Negro, and Vega. 



Distribution tAaps 



One hundred small maps accompanying the 

 drawings summarize the distribution of as many 

 native species by municipalities within Puerto 

 Rico, based upon the unpublished forest inventory 

 by the Commonwealth in 1947-1952 and minor 

 additions. Presence is shown by the number on 

 a white background, in accordance with the num- 

 bers of municipalities in figure 1 and the accom- 

 panying legend. This survey covered 59 of the 75 

 municipalities. The remaining 16 municipalities 

 shown by diagonal shading were omitted because 

 of their limited forested areas, as were two other 

 municipalities on the islands of Culebra and 

 Vieques. Also excluded were the public forests, 

 where other surveys have been made, and the man- 

 grove swamp forests almost wholly within the 

 former. 



These incomplete maps show local distribution 

 in much greater detail than would mai:)s based only 

 upon botanical collections, in spite of certain limi- 

 tations. Some species occur naturally in addi- 

 tional municipalities containing the same foi-est 



environments or regions. Occurrence within a 

 municipality, often limited by environment or al- 

 titude, is not indicated. On sample plots the trees 

 down to a minimum limit of 3.5 inches diameter 

 at breast height (d.b.li.) or 41/4 feet were meas- 

 ured and recorded. However, scattered, less com- 

 mon, and cultivated species were not adequately 

 note<l, and probably are present in some munici- 

 palities adjacent to those mapped. Closely related 

 species of a genus not easily distinguished in the 

 field survey sometimes were grouped together and 

 thus could not be mapped separately. 



Municipalities where an individual species is 

 especially common, that is, among the 10 common- 

 est species in number of trees according to the in- 

 ventory, are listed by number in the text also. 



Distribution Outside Puerto Rico 



Ranges outside Puerto Rico are given for the 

 islands of the West Indies in detail and also for 

 continental tropical America. These ranges are 

 based upon recent botanical floras, tree lists, and 

 monographs supplemented by specimens in the 

 National Herbarium of the United States National 

 Museum. Distribution for many species now is 

 somewhat better known than when summarized by 

 Britton and Wilson (-I). Some species have a 

 broad range through the Greater Antilles (Cuba, 

 Jamaica, Hispaniola, and Puerto Rico) and Les- 

 ser Antilles (Leeward and Windward Islands) to 

 Grenada or Barbados and are present on nearly 

 all the islands except the smallest or those lacking 

 suitable habitats. Thus it has not seemed neces- 

 sary to list all these islands. Nearly all Puerto 

 Rican tree species native also in the island of His- 

 paniola are present in both Haiti and the Domini- 

 can Republic, which countries are not mentioned 

 individually. For those species not ranging 

 througli the Lesser Antilles to Grenada, the south- 

 ernmost island of distribution is recorded. 



Islands near the Venezuelan coast of South 

 America, including Trinidad and Tobago and 

 Bonaire, Curasao, and Aruba of the Dutch West 

 Indies (Windward Islands), have the flora of the 

 South American mainland rather than the We.st 

 Indies. Nearly all native Puerto Rican tree spe- 

 cies also on these islands have a broad distribution 

 in the Caribbean area, such as from Bahamas and 

 Cuba to Trinidad and on the continent from 

 Mexico through Central America to Venezuela or 

 beyond. 



The distribution of those species native or natu- 

 ralized in the United States is given by States, 

 generally only southern Florida, though mention 

 is made of introduced trees planted and hardy in 

 southern Florida and southern California. South- 

 ward on the continent the northernmost and 

 southernmost countries of range limits are stated. 

 Thus, a species recorded from Mexico to Peru and 

 Brazil is native through the countries of Central 

 America and northern South America. Some im- 

 portant cultivated trees are widely distributed 



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