The genus Hypodematium Kunze from Madagascar consists of two species, H. crenatum (Forssk.) Kuhn widely distributed in the Old World and H. delicatulum Rakotondr. & A.R. Sm., sp. nov., endemic from Madagascar, distinguished from all other species of this genus by its sori subapical to intramarginal (vs median to inframedian). These two species are described and illustrated. Identification key and distribution map are provided.
Hypodematiaceae, Hypodematium, Madagascar, identification key, new species.