References to either indigenous uses or the results of controlled assays are numerous for species of Phyllanthus (Euphorbiaceae). These citations have been arranged by subgenus, section, subsection and species and will be published as three separate papers, followed by a paper discussing the apparent clustering of some uses or effects within taxa. This paper, the first of the series, covers the subgenera Isocladus, Kirganelia, Cicca and Emblica.