A new species, Smilax pilosa, is described from the Serra do Brigadeiro State Park, in Minas Gerais State, Brazil. Smilax pilosa is the only Brazilian species of this genus having a dense indumentum covering the entire abaxial surface of the leaf. The new species
is similar to Smilax muscosa Toledo but differs in that the latter has only a sparse indumentum restricted to the veins of the abaxial leaf face. The present study examines the affinity between the two species, reports the newly extended geographic distribution of Smilax muscosa
into Espirito Santo State, and presents a key to the 22 species of Smilax that occur in Minas Gerais.