PHYSIOLOGY OF THE RED MANGROVE. 607 



Engler and Prantl, 1898,^^ regard the group Rhizophoreae as 

 having only five genera with Rhizophora composed of three species 

 — R. mangle, R. conjugata and R. mucronata. This classification 

 is that used in all Floras containing the species. 



SmalP- in all his manuals^^' ^* mentions only Rhizophora mangle, 

 as well as Chapman^^ and other systematic writers. 



The family Rhizophoraceae then belonging in the ]\Iyrtales order, 

 falls naturally into two subfamilies — Rhizophoridese and the Aniso- 

 phylloidese. This is recognized by De Candolle/'^ and Van Tieghem°^ 

 and all the later writers on the family. Some authors, however, 

 divide the family into a triple grouping, with a third head the Leg- 

 notideas, and still others as Baillon^^ arrange the family in a different 

 grouping. This latter author divides fourteen genera into four 

 divisions — I. Rhizophoreae, II. the Baraldieas, III. ^Macarisiese, 

 which is equivalent to the group Legonatideae of Bartling and Cassi- 

 poureas of Meisner, and IV. the Anisophylleae. The affinities of 

 the plants in this family have manifold connections such as the 

 Onagraceae, Loranthaceae, Cornaceas, Lythraceae, as may be seen by 

 the placing of these genera by the earlier authors cited above, and 

 before R, Brown's, 1814,^^ arrangement had been placed in the 

 Caprifoliaceae. All the groupings have been based largely on the 

 relative positions of the perianth and the gynoecium, Baillon's group 

 of Rhizophoreae having concave receptacles and ovary inferior. 

 Style simple and seed exalbuminous, with macropod embryo, ger- 

 minating in fruits on the trees, embraces four genera. These are 

 the ones mostly given in modern floras of oriental countries and are 

 Rhizophora, Ceriops, Brnguiera and Kandelia. They are all repre- 

 sentatives of tropical Asia and Africa, except Rhizophora, which 

 is cosmopolitan in the tropics. 



^1 Engler, A., and Prantl, K., " Die naturlichen Pflanzenfamilien," Teil 

 in., abt. 7, p. 42, 1892. 



52 Small, J. K., " Flora of S. E. United States," p. 834, 1908. 



52 Small, J. K., " Shrubs of Florida," p. 89, 1913. 



5* Small, J. K., " Flora of the Florida Keys," p. 105, 1913. 



53 Chapman, J., " Flora of Southeastern United States," p. 152, 1897. 

 s^' De Candolle, C, " Prodromus," HI., p. 31. 



57 Van Tieghem, Ph., Ann. Soc. Nat., Sen 7, T. VH., p. 376, 1888. 



58 Baillon, H., " Nat. Hist, of Plants," Vol. VI., p. 287. 



59 Brown, R., " Flind, Voj'.," II., p. 549, 1814. 



