"floristic regions"
   Holarctic Kingdom (Holarctis)
     Boreal Subkingdom
       Circumboreal Region
         01 Arctic Province
         02 Atlantic-European Province
         03 Central European Province
         04 Illyrian Province
         05 Euxine Province
         06 Caucasian Province
         07 Eastern European Province
         08 Northern European Province
         09 Western Siberian Province
         10 Altai-Sayan Province
         11 Middle Siberian Province
         12 Transbaikalian Province
         13 Northeastern Siberian Province
         14 Okhotsk-Kamchatka Province
         15 Canadian Province