Source : Webster's Revised Unabridged Dictionary (1913)

Amanita \Am`a*ni"ta\, n. [NL. See {Amanitine}.] (Bot.)
   A genus of poisonous fungi of the family {Agaricace[ae]},
   characterized by having a volva, an annulus, and white
   spores. The species resemble edible mushrooms, and are
   frequently mistaken for them. {Amanita muscaria}, syn.
   {Agaricus muscarius}, is the fly amanita, or fly agaric; and
   {A. phalloides} is the death cup.

Fly amanita \Fly amanita\, Fly fungus \Fly fungus\ . (Bot.)
   A poisonous mushroom ({Amanita muscaria}, syn. {Agaricus
   muscarius}), having usually a bright red or yellowish cap
   covered with irregular white spots. It has a distinct volva
   at the base, generally an upper ring on the stalk, and white
   spores. Called also {fly agaric}, {deadly amanita}.

Source : WordNet®

Amanita muscaria
     n : poisonous (but rarely fatal) woodland fungus having a
         scarlet cap with white warts and white gills [syn: {fly
         agaric}]