The name cryptogams is used fairly widely as a phrase of convenience, although regarded as an obsolete taxonomic term

Linnaean taxonomy

Linnaean taxonomy can mean either of two related concepts:# the particular form of biological classification set up by Carl Linnaeus, as set forth in his Systema Naturæ and subsequent works...

. A cryptogam is a plant (in the wide sense of the word) that reproduces by spore

Spore

In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoa. According to scientist Dr...

s. The term cryptogam means hidden reproduction, and refers to the fact that there is no seed produced; therefore, the cryptogams represent the non-seed bearing vascular plants. Other names, such as "thallophyte

Thallophyte

The thallophytes are a polyphyletic group of non-mobile organisms traditionally described as "relatively simple plants" or "lower plants" with undifferentiated bodies...

s", "lower plants" and "spore plants" are also occasionally used.