Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         Biota
           "neomura"
             Domain Eukaryota Chatton, 1925 - eukaryotes
               "neokaryotes" - mitochondrial eukaryotes
                 "neozoa"
                   Superkingdom Corticata Lankester, 1878
                     Kingdom Plantae Haeckel (1866) - plants
                       Subkingdom Viridiplantae Caval.-Sm. (1981) - green plants
                         Infrakingdom Streptophyta C. Jeffrey (1967)
                           Superphylum Embryophyta
                             "polysporangiophytes"
                               Phylum Tracheophyta Sinnott ex Caval.-Sm. (1998) - vascular plants
                                 Subphylum Euphyllophytina
                                   Infraphylum "Radiatopses" Kenrick & Crane (1997)
                                     "lignophytes"
                                       Class Spermatopsida
                                         "core seed plants"
                                           Subclass Pinidae Cronquist, Takht. & Zimmerm. (1966)
                                             Order Pinalesᵀ Gorozh. (1904) - conifers
                                               Family Pinaceaeᵀ Spreng. ex F. Rudolphi (1830) - pine family
                                                 Subfamily Abietoideae (Bercht. & J. Presl, 1820) Rich. ex Sweet (1826)
                                                   Genus Tsuga (Endl.) Carrière (1855)
                                                     Tsuga canadensis (L.) Carrière (1855) - Canada hemlock
                                                     Tsuga heterophylla (Raf.) Sarg. - western hemlock
                                                     Tsuga sieboldiiᵀ Carrière (1855)
                                                     Subgenus Tsuga subg. Tsugaᵀ (Endlicher, 1847)