318 VEGETATION 



occupy the outer slope of the low ridge of wind-blown sand that skirts the 

 shore. As the crest of this ridge is approached, the sand becomes mixed with 

 a little more humus and there is a rather sudden transition into the higher 

 growth of the next association. 



4. Erithalis-Reynosia {or littoral sand-coppice) Association. — This occu- 

 pies the flat top, not often over 12 or 15 feet wide, of the sand ridge just men- 

 tioned, and -the growth averages about 8 feet, rarely reaching 13 feet in height. 

 Most of the plants mentioned in this last association occur here also, but the 

 principal constituents are Erithalis fruticosa L. (Black torch), Beynosia sep- 

 tentrionalis TJihaji (Darling ■plxim.), Metopium metopium (L.) Small (Poison- 

 wood), Torrubia longifolia (Heimerl) Britton (Blolly), Salmea petrobioides 

 Griseb., Bapanea guianensis Aubl. (Beef -wood), and Ilex krugimia Loes. 

 Genipa clusicefolia Griseb., Acacia choriopJiylla Benth. (Cinnecord), Bumelia 

 loranthifoUa (Pierre) Britton (Milk 'plura) , Bourreria havanensis (L.) Miers 

 (Strong back), Bumelia microphylla Griseb. (Ink-berry), and Vniola racemi- 

 flora Trin. are less commonly present. 



5. The Silver Balm Association covers the inner slope of the ridge and 

 extends to the edge of the marshy depression behind. As the name implies, 

 the silver palm is the character growth here. Its height varies from 8 to 14 

 feet and it is by far the most conspicuous plant of this area. Of the under- 

 growth, TJniola racemiflora Trin. is most abundant. Mixed with it are dwarf 

 specimens of Bithecololium heyense Britton, Torrubia longifolia (Heimerl) 

 Britton, Salmea petrobioides Griseb., Erithalis fruticosa L., Bapanea guian- 

 ensis Aubl., Bourreria havanensis (L.) Miers, Lantana involucrata Sw., Erno- 

 dea littoralis Sw., Corchorus hirsutus L., Beynosia septentrionalis Urban, 

 Cordia bahamensis Urban, and Metopium metopium (L.) Small. 



Peesh-maesh Poemation. — This occupies a long depression behind the 

 beach where the soil is saturated or entirely covered with shallow water. Thatch 

 palms (Inodes palmetto (Walt.) Cook) are abundant on the damp margins 

 of the marsh and a few also penetrate into the shallow water. Cladium effu- 

 sum Torr., Willughbceya heterophylla Small, Centella repanda (Pers.) Small, 

 the attractive, white-flowered Sabbatia companulata (L.) Britton and Ipomea 

 sagittata Cav., with large purple flowers, are also common as marginal plants. 

 Further out large clumps of Anona palustris L. (Custard apple) appeared, 

 and a little Bhizophora mangle L. (Mangrove) in deeper places gave evidence 

 that the water was not quite fresh. This formation is about one-half mile 

 wide and passes northward into the next. 



