Thrinax morrisii H. Wendl., brittle thatchpalm 

 or Key thatchpalm (T. microcarpa Sarg.). North to 

 Broward County. As a palm, protected by State law. 



Thrinax radiata Lodd. ex J. A. & J. H. Schult., 

 Florida thatchpalm (T. floridana Sarg., T. parvi- 

 flora auth.). Formerly northwest to Cape Romano, 

 Collier County, where reported as extinct (Small 



1933). As a palm, protected by State law. 



Trema lamarckiana (Roem. & Schult.) Blume, 

 West Indies trema. Upper Keys from Key Largo to 

 Key Biscayne and adjacent mainland in Dade 

 County. Common locally and spreading on disturbed 

 areas and roadsides. 



DISCUSSION 



This inventory aims to list the rare tropical trees 

 of South Florida and to summarize their natural 

 distribution and their occurrence within preserves. 



The rare tropical trees of South Florida are not 

 protected under the Endangered Species Act. All 

 are native also in the West Indies and would be 

 classed in Florida as border or peripheral species. 

 However, many are protected by State law. These 

 tropical trees are native nowhere else in continental 

 United States. Several species are known from only 

 a few islands or from trees few enough to be counted. 



Most of the 60 species of tropical trees confined to 

 the 3 southernmost counties of South Florida or 

 slightly beyond seem not to be near extinction, hav- 

 ing some protection within parks or preserves. 

 Many rare trees of the Florida Keys are found on Big 

 Pine Key and nearby islands within the National 

 Key Deer Refuge. Likewise, most species of rare 

 trees at the south end of the peninsula or mainland in 

 Dade and Monroe Counties are protected within the 

 Everglades National Park. This park includes a 

 small area at Key Largo Ranger Station on Key 



Largo, one of the Upper Keys. Many of these tropi- 

 cal trees grow also in Matheson Hammock Park 

 south of Miami and in other parks. 



Species at the limits of their ranges are especially 

 subject to fluctuations in the climatic and other en- 

 vironmental factors. For example, infrequent but 

 unusually cold weather below freezing could kill the 

 northernmost individuals of tropical species. Also, 

 rare severe hurricanes could destroy some natural 

 vegetation. Plant diseases and insect pests, some- 

 times introduced, are a further threat. 



A few of the rarest merit additional protection in 

 new preserves. This compilation may be useful in 

 further planning. Propagation in botanical gardens, 

 parks, and arboreta, at least for the rarest species, is 

 another method. The Fairchild Tropical Garden 

 south of Miami already is growing nearly all of the 

 rare tree species listed here. 



Rare plants and animals, especially where pro- 

 tected within National Parks and similar preserves, 

 have considei*able appeal to tourists and therefore 

 possess an indefinite but high monetary value. 



SUMMARY 



South Florida has the greatest collection of rare 

 native trees anywhere in continental United States, 

 about 100 tropical species found nowhere else in the 

 country. This compilation of about 60 species of rare 

 tropical trees of the 3 southernmost counties (Dade, 

 Monroe, and Collier) summarizes their distribution 

 and shows their occurrence within parks and other 

 preserves. All are native beyond in the West Indies 

 and would be classed as border or peripheral 

 species. According to this compilation, a few of the 

 rarest tree species merit additional protection in 

 new preserves. 



This report is the second in a series on rare and 



local native trees of the United States. The En- 

 dangered Species Act of 1973 stressed the need for 

 an inventory. 



Apparently South Florida has no local or endemic 

 tree species. However, 3 endemic varieties are dis- 

 tinguished. 



Only about 13 species of native trees are confined 

 to the Florida Keys and absent from the mainland. 

 Nine tree species are rare and local on the mainland 

 but absent from the Florida Keys. Another is known 

 also from 1 of the uppermost keys. About 38 species 

 of native trees have restricted ranges in both the 

 Florida Keys and the mainland. 



Plate VI. Four tree species of both Florida Keys and mainland. Upper left, Gymnanthes lucida, oysterwood. Upper right. 

 Hippomane mancinella, manchineel (poisonous). Lower left, Schaefferia frutescens, Florida-boxwood. Lower right, Swietenia 

 mahagoni. West Indies mahogany. All drawings one-half natural size except the last, which is one-third. 



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