From 1936 on E. Post has published a series of studies concerning the taxonomy, the ecology, and the geographical distribution of the algae of the so-called Bostrychia-Caloglossa association or Bostrychietum. In this association species of Bostrychia, Caloglossa, Catenella, Murrayella (all Rhodophyta) and other algal genera are involved. Though the Bostrychietum is usually found on aerial roots of mangroves in the upper part of the littoral belt in the tropics, the association is represented also by reduced numbers of species in sheltered habitats in temperate regions. In Post’s monograph on the Bostrychia-Caloglossa association (1936) the number of known species of the genus Bostrychia Montagne in De la Sagra 1842 was reduced from about 50 to 13. In later publications she added two new species.