Medusa Grass is mentioned as a rare herb taken by the merchant Ganga of Mirewater to trade with the witches of Dree. Its name suggests several properties. Firstly it may either cause petrification, cure it, or prevent it from happening, or a mixture of all three. Alternatively, the name may refer to the movement of grass being similar to that of the Snake-like tresses of the Medusa itself. Other grasses exhibiting similar movement, though for different reasons, include Crab Grass, Pilfer Grass, Tangleweed, and Tendril Grass.