It involves Eucaryotic, multicellular, autotrophic plants.
On the basis of presence or absence of seeds, Eichler (1883) classified plants kingdom into two
Cryptogamae : Sex organs are hidden, seeds and flowers absent. Ex: lower plants –
Thallophytes, Bryophytes, Pteridophytes.
Phanerogamae (spermatophytes) : Sex organs are distinct, seeds present Ex: Higher plants–
Gymnosperms and Angiosperms.