Source : Webster's Revised Unabridged Dictionary (1913)

Polyporus \Po*lyp"o*rus\, n.; pl. {Polypori}. [NL., fr. Gr.
   poly`s many + ? a pore.] (Bot.)
   A genus of fungi having the under surface full of minute
   pores; also, any fungus of this genus.

   Note: {Polyporus fomentarius} was formerly dried and cut in
         slices for tinder, called amadou. {P. betulinus} is
         common in America, and forms very large thick white
         semicircular excrescences on birch trees. Several
         species of {Polyporous} are considered edible.