Synopsis of Manihot Species (Euphorbiaceae) with Non-lobed or Pinnately Lobed Leaves

A synopsis of 20 species of Manihot Mill. with non-lobed or pinnately lobed leaves is presented. Six of these species were included in the section Brevipetiolatae Pax by Rogers and Appan in the latest treatment of the genus. Molecular analyses show this is not a monophyletic section, although it is useful as a practical matter to treat this as a morphologically readily delimited group. We evaluate the species previously included in section Brevipetiolatae sensu Rogers and Appan, typify names where necessary, and synonymize the section. Twenty species are clarified and six lectotypes are designated. Three species previously put into synonymy, M. brachystachys Pax & K. Hoffm., M. linearifolia Mull. Arg., and M. mattogrossensis Pax & K. Hoffm., are here resurrected, and M. graminiformis M. Mend. & T. B. Cavalc. is described as a new species. An identification key and comments on the most similar morphological species, as well as ecological aspects and distribution for each species, are included.