Cryptogams

A fungus (: fungi or funguses) is any member of the group of eukaryotic organisms that includes yeast and mold as well as the mushroom. These organisms are classified in the biological kingdom Fungi.

thumb|A tree covered with leafy foliose lichens and shrubby fruticose lichens

thumb|An example of moss (Bryophyta) on the forest floor in Broken Bow, Oklahoma

The lycophytes, when broadly circumscribed, are a group of vascular plants that include the clubmosses. They are sometimes placed in a division Lycopodiophyta or Lycophyta or in a subdivision Lycopodiophytina. They are one of the oldest lineages of extant (living) vascular plants; the group contains extinct plants that have been dated from the Silurian (ca. 425 million years ago). Lycophytes were some of the dominating plant species of the Carboniferous period, and included the tree-like Lepidodendrales, some of which grew over in height, although extant lycophytes are relatively small plants.

A pteridophyte is a vascular plant with xylem and phloem that reproduces by means of spores. Because pteridophytes produce neither flowers nor seeds, they are sometimes referred to as "cryptogams", meaning that their means of reproduction is hidden. They are also the ancestors of the plants we see today.

thumb|Polystichum setiferum, a fern thumb|Grimmia pulvinata, a moss thumb|Pelvetia canaliculata, a brown alga thumb|Hypholoma fasciculare, a fungus

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