Source : Webster's Revised Unabridged Dictionary (1913)

Convener \Con*ven"er\, n.
   1. One who convenes or meets with others. [Obs.]

   2. One who calls an assembly together or convenes a meeting;
      hence, the chairman of a committee or other organized
      body. [Scot.]

Source : WordNet®

convener
     n : the member of a group whose duty it is to convene meetings