Kingdom Chlorobiota C.Jeffrey ex Doweld (2001) - plants see Subkingdom Viridiplantae Caval.-Sm. (1981) Subkingdom Pteridobiotina Britton & A. Br. (1896) Superdivision Cycadophytanae Doweld (2001) see Superphylum Cycadophytanae Doweld (2001) Division †Pteridospermatophyta Meyen Class †Lyginopteridopsida Novák (1961) Order †Lyginopteridales Havlena (1961) Family †Physostomataceae A.G. Long (1975) [monotypic] Genus †Physostoma Williamson (1875)