Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         ["vegetable kingdom"]
           ["Cryptogams"]
             [Class Acrogens Lindl.]
               [Alliance Filicales Dumort.]
                 1 [Natural order Filices Juss. (1789)]
                 1.0 [Order Polypodiaceae J.Presl & C.Presl] see Order Filices L. (1753), nom. inval.
                 2 [Natural order Ophioglossaceae Martynov]
                 3 [Natural order Equisetaceae Michx. ex DC.]
                 4 [Natural order Marsileaceae Mirb.]
                 5 [Natural order Lycopodiaceae P.Beauv. ex Mirb.]