Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       Astra Plinius - celestial bodies
         Universe
           (Supercluster) Virgo-Hydra-Centaurus Supercluster
             (Supercluster) Virgo Supercluster
               (Cluster) Local Group
                 (Galaxy) Milky Way Galaxy veter.
                   (Spiral arm) Orion Arm
                     (Region) Local Bubble
                       Local Interstellar Cloud
                         (Planetary system) Solar System
                           (Planet-satellite system) Earth System
                             (Planet) Earth veter.
                               "spheres" (Earth)
                                 (Sphere) Biosphere (Earth) - zone of life
                                   "terrestrial and freshwater ecoregions"
                                     (Bioregion) New World
                                       (Biogeographic realm) Nearctic
                                         "terrestrial ecoregions" (Nearctic)
                                           (Ecoregion complex) Northern Prairie (Nearctic)
                                             (Terrestrial ecoregion) Northern short grasslands (Nearctic)
                                               "Canada" (Northern short grasslands)
                                                 1 "Alberta" (Canada; Northern short grasslands)
                                                 2 "Saskatchewan" (Canada; Northern short grasslands)