TRANSACTIONS OF WAGNER 

 70 



VEGETATION OF SOUTH FLORIDA 



and southern ends of Key Largo are low and covered with mangroves. On this 

 island, the low salt flats are controlled by the black-mangrove, Avicennia 

 nitida Jacq., and wherever a salt channel is reached, such a channel is 

 lined with red-mangroves. Long Key has a large reentrant bay at its northern 

 end with its shore lined with this type of littoral swamp vegetation. My notes 

 of June, 1912, continue the observations from Long Key, which was visited in 

 December, 1910. Grassy Key is mangrove fringed and has mangrove flats. 

 The lower end of Key Vaca is a mangrove flat, while Little Duck Key is almost 

 entirely a flat covered with mangroves. Bahia Honda Key has flat mangrove 

 areas and salt lagoons with islands of these trees raised on their stilt-like 

 roots. Similar flats and fringing mangrove swamps are found on Summer- 

 land, Big Pine, Cudjoe, Sugar Loaf, Saddle Bunch, Big Coppit keys, followed 

 by a succession of low mangrove islands around Rockland and Boca Chica 

 keys, while Key West is partly fringed with a dense, impenetrable thicket of 

 low mangrove trees not over 3-3.5 meters (10-12 feet) tall. 



The south shore of the peninsula of Florida, touching the Bay of Florida, 

 as far as Flamingo, is bordered by a dense and wide mangrove thicket, which 

 extends north until it blends with the coastal prairie-everglade. Here the 

 thicket begins to thin out and the trees become scattered.* These scattered 

 trees extend some distance back into the coastal prairie-everglade where they 

 become smaller, lower (not over i meter tall) , and reduced to a few leafy branches 

 raised on widely extended prop roots. (Plate II, Fig. i.) The leaves assume 

 here a yellowish-green color. Here the trees grow in fresh water and their 

 presence is due to survival from a time when the mangrove swamp covered all 

 of the southern end of the peninsula. As the dry-land conditions became more 

 pronounced, the northern edge of the coastal swamp was invaded by prairie- 

 everglade vegetation. The mangrove trees were gradually suppressed until 

 surrounded with grass and sedge vegetation and almost completely choked by 

 it, a few low, scattered mangrove trees of a yellowish-green color remaining 

 under the stress of the competition of the everglade-prairie plants. (Plate 

 II, Fig. i.) 



The uncertainty as to the outline of White Water Bay, Ponce de Leon Bay 

 and the Bay of Ten Thousand Islands is on account of the islands of mangrove 



* Compare the accounts of Harper, R. M.: Report on Peat, Third Annual Report Florida Geo- 

 logical Survey, 228, 233, 327; Tramping and Camping on the southeastern Rim of the Everglades 

 Florida Review, 4; 154-155. 1910. 



