Morphological and nomenclatural investigations for two critical Mediterranean species of Elatine, i.e., E. macropoda gussonei, as well their correct distribution in Sicily, are discussed. These names lectotypified on herbarium specimens kept, respectively, at NAP FI. The morphological carried out both the types, several living dried material collected southern Lampedusa, Malta (loci classici in...

The neotropical genus Potamium as described by Mitten (1869) included species that had little more in common than a growth form adapted to a semi-aquatic habitat. Brotherus divided the genus in section Eu-Potamium and section Potamiopsis, based on peristome characters. This study shows that all species of section Eu-Potamium belong to Sematophyllum, including P. lonchophyllum which was designat...