As Petalium (Metapetalium ); currently valid as subgenus according to Hallan. From White, 1982: The name was published by Espanol in 1967 and 1968, but because no type-species was selected, either from the 3 species assigned in 1967 or from the 5 species assigned in 1968, the subgenus was not validly proposed until 1970.