A cryptogam (scientific name Cryptogamae) is a plant, in the broad sense of the word, or a plant-like organism that shares similar characteristics, such as being multicellular, photosynthetic, and primarily immobile, that reproduces via spores rather than through flowers or seeds.
This broader definition can include algae, fungi, and certain bacteria (like cyanobacteria), even though they may belong to different biological kingdoms.
A seed plant or spermatophyte (from Ancient Greek σπέρμα (spérma) 'seed' and φυτόν (phutón) 'plant'; lit. 'seed plant'), also called a phanerogam (taxon Phanerogamae) or a phaenogam (taxon Phaenogamae), is any plant that produces seeds. It is a category of embryophyte (i.e. land plant) that includes most of the familiar land plants, including the flowering plants and the gymnosperms, but not ferns, mosses, or algae.
The term phanerogam or phanerogamae is derived from Ancient Greek φανερός (phanerós), meaning "visible", in contrast to the term "cryptogam" or "cryptogamae" (from Ancient Greek κρυπτός (kruptós) 'hidden', and γαμέω (gaméō), 'to marry'). These terms distinguish those plants with hidden sexual organs (cryptogamae) from those with visible ones (phanerogamae).