23231232
[Water ferns] (Salvinia, Marsilea)
- 0 Hegel's 'System of Science'
- 1 Logic (Thinking of Thinking, Science of Science)
- 2 Nature (science of matter)
- 3 Spirit/Mind (Science of humanities)
- 21 Mechanics
- 22 Physics (including Chemistry)
- 23 Organism / Life (Subjectivity)
- 231 The Earth (Geology)
- 232 Plant life (biology of the vegetal)
- 233 Animal life (biology of the animal)
- 2321 Shapes of plant life
- 2322 Plant relation to its enviroment
- 2323 Genus process of the plants
- 23231 [Special plant species]
- 23232 Beginnings of sexual organs
- 23233 Fertilization
- 232311 [Thallophytes] (without root, shoot or leaf)
- 232312 [Spore plants] (alternation of generations, dispersal by spores)
- 232313 [Seed plants] (seed instead of spore)
- 2323121 [Mosses] (without vascular tissue)
- 2323122 [Clubmosses and horsetails] (first vascular tissue, small leaves)
- 2323123 [Ferns] (frond as the developed leaf)
- 23231231 [Whisk ferns and adder's-tongues] (primitive)
- 23231232 [Water ferns] (Salvinia, Marsilea)
- 23231233 [True ferns] (polypody, male fern, tree ferns)