"The plant has many uses besides serving as a raw product in the manufacture of rence paper…from the stem the rence growers can make reed boats, sails, mats, cords and a kind of fibrous cloth; further it's pith is edible…"

Raiders of Gor    page 7

  (A water plant which is used for food, pressed into paper or woven into cloth. The pith (or center of the stem) is edible…it is made into a paste or porridges, or made into rence beer and drank from flagons.)