I9I4-] SOUTHEASTERN NORTH AMERICA. 135 



inus, and in all of these genera or closely related ones there are ex- 

 isting tropical forms. None extend beyond the warmer parts of 

 the temperate zone and some of these as in the case of Juglans and 

 Fraxinus indicate in their compound leaves their tropical ancestry, as 

 was first pointed out by Grisebach. The ferns are all tropical types 

 and their relative unimportance in the Wilcox flora furthermore in- 

 dicates that the major part of this flora is a strand flora. This is 

 shown more especially by forms like the Nipa palm which never 

 grows outside of tidal marshes, by Conocarpus, Laguncularia and 

 Avicennia which inhabit like situations; by coastal marsh or lagoon 

 plants like Canna, Trapa and Sabalites; and by the large number of 

 strand types that inhabit beaches or the jungle behind the beach 

 ridges or dunes. The more striking of these genera are Myrica, 

 Artocarpus, Ficus, Coccolobis, Pisonia, Anona, Capparis, Chryso- 

 balanus, various Lauraceae, Apocynacese, Sapotaceae and Legumino- 

 sse, Fagara, Dry petes, Metopium, Ilex, Celastrns, Sapindus, Dodoncea, 

 Reynosia, Rhamnus, Myrcia, Eugenia, Laguncularia, Combretum, 

 Tcrminalia, Cordia, Citharexylon, Exostema and Guettarda. 



It needs but a slight acquaintance with the existing Antillean 

 flora or that of the Florida keys, or in lieu of actual acquaintance a 

 perusal of the as yet too few ecological discussions of the flora of 

 the American tropics or even of Schimper's classic Indo- Malayan 

 strand flora to see at once that the general facies of the Wilcox flora 

 is overwhelmingly that of a strand flora of which some of the 

 elements indicate that they grew on the sandy beaches, others in 

 muddy tidal flats, others between or behind dunes or beach ridges, 

 and others in estuary bayous or marshes. None of the forms can 

 certainly be considered as inland or upland types. Even genera like 

 Banksia which is not usually considered a coastal type in the existing 

 flora furnishes Banksia marginata Cav. to the coastal sand dunes of 

 South Australia (Tepper) and several others species of the genus 

 occur on the dunes of Queensland, Victoria and western Australia. 



Little has been written of the plant associations of the American 

 tropics and collectors notes almost always fail to adequately describe 

 habitats. While the marginal Wilcox lands were low there was such 

 a large area of continent to the northward to draw from, and the 

 long coast furnishes such varied edaphic conditions, that the flora 



