Classification of Plants

Older classification schemes lumped plants and animals apart mainly by nutrition (photosynthetic vs. ingestive), locomotion (fixed vs. motile) and the presence or absence of a cell wall — and under that scheme, Bacteria, Fungi, Algae, Bryophytes, Pteridophytes, Gymnosperms and Angiosperms were all bundled together as 'plants'. Molecular evidence eventually showed that Bacteria and Fungi are fundamentally different lineages, and they were moved into their own separate kingdoms, leaving the modern Plant Kingdom (Plantae) as the five groups above.

The currently accepted outline treats Embryophyta (plants that develop a multicellular embryo protected inside the parent) as splitting first into Bryophyta and Tracheophyta (the vascular plants). Tracheophyta in turn splits into Pteridophyta and Spermatophyta, and Spermatophyta finally splits into Gymnospermae and Angiospermae. An older, informal way of saying the same thing groups Algae, Bryophyta and Pteridophyta together as Cryptogamae ('hidden reproduction' — non-flowering, non-seed-producing) and Gymnospermae plus Angiospermae as Phanerogamae ('visible reproduction' — seed- and, in angiosperms, flower-producing). …