Source : Webster's Revised Unabridged Dictionary (1913)

Liverwort \Liv"er*wort`\, n. (Bot.)
   1. A ranunculaceous plant ({Anemone Hepatica}) with pretty
      white or bluish flowers and a three-lobed leaf; -- called
      also {squirrel cups}.

   2. A flowerless plant ({Marchantia polymorpha}), having an
      irregularly lobed, spreading, and forking frond.

   Note: From this plant many others of the same order
         ({Hepatic[ae]}) have been vaguely called liverworts,
         esp. those of the tribe {Marchantiace[ae]}. See Illust.
         of {Hepatica}.

Source : WordNet®

liverwort
     n : any of numerous small green nonvascular plants of the class
         Hepaticopsida growing in wet places and resembling green
         seaweeds or leafy mosses