in 



FEB. 1907. FLORA SAND KEYS OF FLORIDA MILLSPAUGH. 241 



SEQUENCE OF APPEARANCE. 



From a somewhat wide field study of isolated insular and strand 

 formations in the Antillean region I have come to the conclusion that 

 the order of precedence in the clothing of the wave-formed sand keys 

 of Florida has been substantially as follows: 



1. Sesuvium portulacastrum (Aquavectent). 



2. Cakile fusiformis (Aquavectent). 



3. Euphorbia buxifolia (Avevectent).* 



( Cenchrus tribuloides /A 

 4 ' | Cyperus brunneus (Avevectent).* 



5. Uniola paniculata (Aquavectent). 



6. Andropogon glomeratus (Avevectent).* 

 ( Suriana maritima 



7" \ Tournefortia gnaphalodes (Avevectent).* 



j Borrichia arborescens , . 

 8 " ] Iva imbricata (Avevectent).* 



9. , Ambrosia hispida (Aquavectent). 



Of the mangrove-formed strands the order of precedence, from 

 the mangrove nucleus toward the strand, appears to be: 

 i. Rhizophora mangle (Aquavectent). 



j Avicennia nitida ,. , 



I Laguncularia racemosa ^ 



3. Conocarpus erecta (Avevectent). 

 ( Batis maritima 



4. < Salicornia ambigua (Avevectent). 

 ( Dondia linearis 



The open or sea margin of the mangrove-formed strand vegetates 

 synchronously with the mangrove border in the usual sequence of the 

 sand keys. 



An interesting comparative map, that may be consulted in illus- 

 tration of these conclusions, is that of Woman Key, where we have 

 not only an open or sea islet strand on the eastern part of the key, 

 but also an isolated mangrove islet on the western part still entirely 

 surrounded by a Rhizophora colony upon which there is an utter 

 absence of species depending upon the sea for dissemination. 



* Through the medium of the feet of sea birds. 



