The Collaborative International Dictionary of English v.0.48:

Cryptogamian \Cryp`to*ga"mi*an\ (kr?p`t?-g?"m?-an), Cryptogamic
\Cryp`to*gam"ic\ (kr?p`t?-g?m"?k), Cryptogamous
\Cryp*to"gam*ous\a.
   Of or pertaining to the series Cryptogamia, or to plants of
   that series.
   [1913 Webster]

WordNet (r) 3.0 (2006):

cryptogamic
    adj 1: of or relating to a cryptogam [syn: cryptogamic,
           cryptogamous]