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) Old World
                                       (Biogeographic realm) Palearctic
                                         (Desert) Sahara (Africa)
                                           1 (Terrestrial ecoregion) Atlantic coastal desert (Palearctic)
                                           2 (Terrestrial ecoregion) North Saharan steppe and woodlands (Palearctic)
                                           3 (Terrestrial ecoregion) Saharan halophytics (Palearctic)
                                           4.1 (Terrestrial ecoregion) Sahara desert (Palearctic)
                                           4.2 (Terrestrial ecoregion) West Saharan montane xeric woodlands (Palearctic)
                                           4.3 (Terrestrial ecoregion) Tibesti-Jebel Uweinat montane xeric woodlands (Palearctic)
                                           5 (Terrestrial ecoregion) South Saharan steppe and woodlands (Palearctic)