The Collaborative International Dictionary of English v.0.48:

cleistothecium \cleistothecium\ n.
   the closed spore-bearing structure of some fungi (especially
   Aspergillaceae and Eurysiphaceae) from which spores are
   released only by decay or disintegration; -- called also
   cleistocarp.

   Syn: cleistocarp.
        [WordNet 1.5]

The Collaborative International Dictionary of English v.0.48:

cleistocarp \cleistocarp\ n.
   the closed spore-bearing structure of some fungi (especially
   Aspergillaceae and Eurysiphaceae) from which spores are
   released only by decay or disintegration; -- called also
   cleistothecium.

   Syn: cleistothecium.
        [WordNet 1.5] Cleistogamic

WordNet (r) 3.0 (2006):

cleistothecium
    n 1: closed spore-bearing structure of some fungi (especially
         Aspergillaceae and Erysiphaceae) from which spores are
         released only by decay or disintegration [syn:
         cleistothecium, cleistocarp]