Kingdom [Plantae] Haeckel (1866) - plants
   Division Pteridophyta Schimp. (1879) see Subphylum Pteridophytina (Eichler) Cavalier-Sm. (1998)
     Class Lycopsida - club-mosses see Class Lycopodiopsida Bartl. (1830)
       Order Isoetales Prantl (1874) - quillworts see Order Isoëtales Prantl (1874)
         1 Family Isoetaceae Rchb. (1828) see Family Isoëtaceae Rchb. (1828)
         2 Family †Chaloneriaceae Pigg & G.W.Rothwell (1983)