America’s Pacific species of Rhizophora

When studying the Atlantic species of Rhizophora (Breteler 1969), I came to the conclusion that of the three species occurring within the area, R. harrisonii Leechm. had to be considered as a hybrid between the other two species, i.e. R. mangle L. and R. racemosa G. F. W. Mey. This conclusion was based on morphological, ecological, and phenological grounds and was supported by the results of pollen investigations by J. Muller. The Pacific species of the American continent were not discussed in the first paper, but a later publication was announced, dealing with these. Hou (1960) reduced the two Pacific species of America, R. brevistyla Salvoza and R. samoensis (Hochr.) Salvoza, into synonymy of R. harrisonii and R. mangle respectively. At that time the available material did not show the presence of R. racemosa on America’s Pacific coast. At present this situation has not changed, although Prance et al. (1975) report two collections of R. racemosa from the coast of Ecuador. The possible presence of R. racemosa on the Pacific coast will be discussed more detailed below.