1. Leaves with a dense cover of silvery trichomes on both faces .............................................................................................................2

1′. Leaves without a dense cover of silvery trichomes on both faces .......................................................................................................3

2. Caudex generally inconspicuous, never growing horizontally. Leaves coriaceous. Pyxidia 3-seeded [Serra do Caparaó, eastern Brazil]......................................................................................... .........................................................................................Plantago bradei

2′. Caudex elongated, growing horizontally. Leaves chartaceous. Pyxidia 1–2-seeded [southern Santa Catarina, southern Brazil]........................................................... ................................................................................................................. Plantago rahniana

3. Leaves with the abaxial face densely covered with silvery/whitish trichomes, giving a silky appearance..........................................4

3′. Leaves with the abaxial face glabrous to pilose, but never densely covered with silvery/whitish trichomes....................................5

4. Leaves narrow-lanceolate. All sepals glabrous [southern Paraná and western Santa Catarina, southern Brazil]............................................................................................................Plantago campestris

4′. Leaves linear. Posterior sepals pilose on the keel [Uruguay, Paraguay and southern Brazil] ............................................................................................................................................................................. Plantago commersoniana

5. Leaves membranaceous, glabrous (even when young). Seeds with the ventral side deeply concave [Chapada dos Veadeiros, central Brazil].................... ............................................................................................ Plantago veadeirensis

5′. Leaves coriaceous, pilose (but gradually losing trichomes as they senesce). Seeds with the ventral side plane to slightly concave................................................ ...................................................................................................................................................... 6

6. Thickened taproot present, tuberous roots absent. Trichomes on leaves and scapes with conspicuous dark cellular articulations. Pyxidia 1–2-seeded [eastern Paraná, southern Brazil] ..................................................................................... Plantago hatschbachiana

6′. Roots formed of several subcylindrical tubers. Trichomes on leaves and scapes without conspicuous dark cellular articulations. Pyxidia 1-seeded [eastern Bolivia] ............................................................................................................................... Plantago pyrophila