The Collaborative International Dictionary of English v.0.48:

Cryptogam \Cryp"to*gam\ (kr?p"t?-g?m), n. [Cf. F. cryptogame.
   See Cryptogamia.] (Bot.)
   A plant belonging to the Cryptogamia. --Henslow.
   [1913 Webster]

WordNet (r) 3.0 (2006):

cryptogam
    n 1: formerly recognized taxonomic group including all
         flowerless and seedless plants that reproduce by means of
         spores: ferns, mosses, algae, fungi