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.
Adiantum, Pteridaceae, Madagascar, new species