Historically recognized plant taxa

thumb|Lichens are some of the organisms included in several definitions of the Thallophyte group. Thallophytes (Thallophyta or Thallobionta) are a polyphyletic group of non-motile organisms traditionally described as "thalloid plants", "relatively simple plants" or "lower plants". They form a division of kingdom Plantae that include lichens and algae and occasionally bryophytes, bacteria and slime moulds. Thallophytes have a hidden reproductive system and hence they are also incorporated into the similar Cryptogamae category (together with ferns), as opposed to Phanerogamae. Thallophytes are d

thumb Cormophytes (Cormophyta) is a historical term seldom used today for the plants that are differentiated into roots, stems and leaves. These plants differ from thallophytes, whose body is referred to as the thallus, i.e. a simple body not differentiated into leaves and stems. Definitions have varied, notably about whether mosses and liverworts are included.

The anthophytes are a paraphyletic grouping of plant taxa bearing flower-like reproductive structures. The group, once thought to be a clade, contained the angiosperms – the extant flowering plants, such as roses and grasses – as well as the Gnetales and the extinct Bennettitales.

Archegoniatae was a higher taxonomic term that indicated those embryophytes having a female sexual organ in the form of an archegonium. The term was first introduced by the Russian botanist Ivan Nikolaevich Gorozhankin (1848–1904) in 1876 to indicate a division including bryophytes, pteridophytes and gymnosperms in contrast to the Gynoeciatae (Angiosperms) with a more complex female organ. It has also been used as a general term for mosses (bryophytes) and ferns (pteridophytes), for instance by Douglas Campbell.

Psilophytopsida is a now obsolete class containing one order, Psilophytales, which was previously used to classify a number of extinct plants which are now placed elsewhere. The class was established in 1917, under the name Psilophyta, with only three genera (Rhynia, Horneophyton and Psilophyton) for a group of fossil plants from the Upper Silurian and Devonian periods which lack true roots and leaves, but have a vascular system within a branching cylindrical stem. The living Psilotaceae, the whisk-ferns, were sometimes added to the class, which was then usually called Psilopsida. This classif

species of plant