We don't have synonyms for cryptogam yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are cryptogram, cryptonym and cryptogams.
(n) :
Any plant that reproduces using spores (rather than seeds), formerly placed in the taxonomic group Cryptogamae, which included ferns, mosses, algae, fungi, lichens and liverworts.
(n) :
Any plant that reproduces using spores (rather than seeds), formerly placed in the taxonomic group Cryptogamae, which included ferns, mosses, algae, fungi, lichens and liverworts.