Now you tell one (1926)

The Liars Club is holding their contest to see who can tell the most unbelievable story, with a gold medallion waiting to be awarded to the winner. Disappointed with the other members' bland efforts, one member brings in Charley Bowers, who has an extraordinary tale to tell. Charley claims to have invented a magic potion that enables him to grow absolutely anything by a simple grafting process, and he proceeds to tell his story to the club.