This quest is no longer available within the game.
Greetings once again, <name>! Our need for runecloth is constant, and we can always use additional resources if you are willing to part with them. For an additional stack of twenty runecloth, I will make sure that you are recognized for your continuing efforts on behalf of Darnassus.
Whenever you are ready to hand in the stack of runecloth, I'll accept it.