Rakotondrainibe, F. & A. Jouy (2016). A new species and a new synonymy in the genus Selaginella P. Beauv. (Lycopodiophyta, Selaginellaceae) from Madagascar. Candollea 71: 143–148. In French, English and French abstracts. DOI : http//dx.doi.org/10.15553/c2016v711a17A new Malagasy species of Selaginella P. Beauv. (Lycopodiophyta, Selaginellaceae) is described and a new synonymy in the same genus is established. The new species Selaginella rasoloheryi Rakotondr. belongs to the subgenus Heterostachys Baker; it differs from all other Africano-Malagasy species of this subgenus by the main stem being prostrated throughout its entire length, without soboles, with rhizophores and ramifications unbranched, and with median leaves strongly acuminate. Selaginella rasolohery has a close affinity to Selaginella ciliaris (Retz.) Spring, an asiatic and oceanic species, but differs from it by more pronounced leaf dimorphism in both vegetative and fertile shoots, median leaves longer acuminate, strobili less compact and lateral sporophyll carina narrow and dentate (vs. carina large and ciliate in Selaginella ciliaris). The new synonymy between Selaginella fissidentoides (Hook. & Grev.) Spring f.fissidentoides and Selaginella fissidentoides f. ovata Stefanović & Rakotondr. is established after observation of numerous Malagasy specimens recently collected between 1997 and 2015 after the publication of the first Selaginella revision for Madagascar and the Comoro Islands.