With some researches in Togo, the authors identify an unrecognized vegetal formation for tropical Africa, the tall herb formation, illustrated by the new Marantochloo purpureae—Anubiadetum giganteae, described by a phytosocio- logical table and family, biological, pollination and phytogeographical spectra. Some comparisons with other African tall herb communities allow to describe a new systematic structure, the S(Marantaceae-Commelinaceae).
