PITH (O.E. pitha, cognate with Du. pit, kernel of a nut), properly the medulla, the central column of spongy cellular tissue, in the stems of dicotyledonous plants (see PLANTS: Anatomy). The word is thence applied to the spinal cord or marrow in animals, to the medullary end of a hair, and to that which forms the central part or core of any object or substance; hence, figuratively, vigour, energy, concentrated force. Very light hats or helmets are made of the dried pith of the Indian spongewood or hat plant (Asschynomene aspera, the native name being Solah). These pith hats are worn by Europeans in India and the East. The Chinese Ricepaper-tree (Aralia or Fatsia papyri/era), from the pith of which the delicate white film known as " rice-paper " is made, is also known as the pith-plant.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)