Natura - nature actualia - actual entities Mundus Plinius - physical world naturalia - natural bodies Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020] Domain Bacteria Woese et al. 2024 Kingdom Bacillatiᵀ (Gibbons and Murray 1978) Oren and Göker 2024 Phylum Cyanobacteriota Oren et al. 2022 Class Chroococcophyceaeᵀ Hollerbach et al. 1953 Order Nostocales corrig. Borzì 1914 Family Stigonemataceae corrig. (Agardh ex Bornet and Flahault 1886) Borzì 1892 nom. cons. Genus Sirosiphon Kützing ex Frank 1886