Adiantum papilio Rakotondr. & Hemp, sp. nov. (Pteridophyta, Pteridaceae), une nouvelle espèce endémique de Madagascar

A new species of Adiantum (A. papilio Rakotondr. & Hemp, sp. nov.) is described and illustrated from the Antsiranana region in northern Madagascar. Unlike the others Adiantum L. species from Madagascar, A. papilio Rakotondr. & Hemp, sp. nov. has 1-pinnate fronds with opposite to subopposite pinnae. Its morphology is similar to A. bal­fourii Baker from Erythrea but with an erect rhizome, obdeltoid pinnae with lobed not denticulate margin, and oblong to round not linear indusia.