The Collaborative International Dictionary of English v.0.48:

Mythopoeic \Myth`o*poe"ic\, a. [Gr. myqopoio`s making myths;
   my^qos myth + poiei^n to make.]
   Making or producing myths; giving rise to mythical
   narratives.
   [1913 Webster]

         The mythopoeic fertility of the Greeks.  --Grote.
   [1913 Webster]