FREE INSTITUTE OF SCIENCE 
VEGETATION OF SOUTH FLORIDA 
65 
known as saffron-plum, ant’s-wood, downward-plum. Low bushy forms of 
oak are found on the highest terrace of the upper beach growing with clumps 
of Yucca aloifolia L. So much for the vegetation of the beaches of north- 
eastern Florida by way of comparison with those of the southern end of the 
state, which is found as indicated previously on essentially the same character 
of silicious sand. 
Beach Formation, Ocean Beach Opposite Miami.—Several visits were 
made to the sea-beach opposite Miami, readily reached by small excursion 
steamer and now by a bridge across Bay Biscayne. It is situated on the 
peninsula that extends southward from the mainland, and in line with the 
Upper Sand keys, as Virginia, Biscayne and Soldier keys. 
'The width of the lower and middle beach on the Atlantic coast of South 
Florida is not as great as in North Florida, perhaps because of the steep off- 
shore character of the land mass past which the Gulf Stream flows. 'The upper 
beach slopes gradually to the low dune on the crest of which the introduced 
cocoanut palm grows in an unbroken line along the shore. The upper beach 
is characterized by the long creeping stems of Ipomoea pes-capre (L.) Sweet, 
associated with prostrate plants of similar habit, Canavalia lineata (Thunb.) 
DC. The grayish plant, Croton punctatus Jacq., forms low clumps on the 
upper beach together with the silky canescent shrub, Tournefortia gnaphalodes 
(Jacq.) R.B., and Sesuvium portulacastrum L. The seaside-oats, Uniola 
paniculata L., covers the upper beach and extends over the crest of the frontal 
dune and a few clumps of the Spanish-bayonet, Yucca aloifolia L., are present 
to break the almost continuous growth of swaying grass panicles on long flexu- 
ous scapes. 
Beach Formalion, Sanibel Island.—Sanibel Island, separated from the 
mainland by San Carlos Bay, is at the mouth of the Caloosahatchee River 
and is the southwest island of the group which includes Captiva, Useppa, 
Gasparilla, and Pine islands. Its long diameter is approximately east and west. 
Its convex and south shore is exposed to the storms of the Gulf of Mexico, 
while its northern, or embayed irregular shore, is on the San Carlos Bay 
side. Two beaches, therefore, may be distinguished, which we will desig- 
nate as the Gulf beach and the bay beach. 
The vegetation of the exposed Gulf beach is somewhat different from 
that of the bay beach and will be described first (Plate I, Fig. 1). The lower 
beach is without visible living plants and is the widest of the three divisions of 
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