Arundo micrantha Lam. (Poaceae) was validly published by Lamarck in 1791 but has been overlooked in the literature. Based on recent taxonomic and phylogenetic studies, this name is rehabilitated to designate a circum-Mediterranean taxon, with Arundo mauritanica Desf. and Arundo mediterranea Danin as later synonyms. For the first time, Arundo micrantha is recorded in the Flora of France based on two rediscoveries (Golfe-Juan and Ste-Lucie Island) and identifications in the wild, thanks to indications of older specimens in herbaria G, MARS, MPU and P. However, these two populations of Arundo micrantha are under severe threats and this species must be considered as Critically Endangered in France following IUCN Red List Categories.