The Collaborative International Dictionary of English v.0.48:

Conceptacle \Con*cep"ta*cle\, n. [L. conceptaculum, fr.
   concipere to receive. See Conceive.]
   1. That in which anything is contained; a vessel; a receiver
      or receptacle. [Obs.] --Woodward.
      [1913 Webster]

   2. (Bot.)
      (a) A pericarp, opening longitudinally on one side and
          having the seeds loose in it; a follicle; a double
          follicle or pair of follicles.
      (b) One of the cases containing the spores, etc., of
          flowerless plants, especially of algae.
          [1913 Webster]