Barrelstalk was a fungus that grew in the Underdark, named for its barrel-like shape. It had a hard, woody outer surface, but the inside was hollow and could contain about 5 to 8 gallons of potable water. The inner rings of the barrelstalk were made from an edible pulp. A typical specimen yielded about 5 to 10 pounds of bland, but nonetheless nutritious, food.
Once matured at about ten years of age, barrelstalk produced spores and its flesh turned poisonous, making it useless as a source of food and water.