[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Domain Bacteria Woese et al. 1990
     Phylum "Actinobacteria" Garrity and Holt 2001
       Class "Actinobacteria" Stackebrandt et al. 1997
         Subclass Actinobacteridae Stackebrandt et al. 1997 see Class Actinobacteria Stackebrandt et al. 1997
           Order Actinomycetales Buchanan 1917 (Approved Lists 1980)
             Suborder Propionibacterineae Rainey et al. 1997
               Family Propionibacteriaceae Delwiche 1957 (Approved Lists 1980)
                 Genus Arachnia Pine and Georg 1969 (Approved Lists 1980) see Genus Propionibacterium Orla-Jensen 1909 (Approved Lists 1980)