The Collaborative International Dictionary of English v.0.48:

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.
      [1913 Webster]

   2. A flowerless plant (Marchantia polymorpha), having an
      irregularly lobed, spreading, and forking frond.
      [1913 Webster]

   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.
         [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Hepatica \He*pat"i*ca\, n.; pl. Hepatic[ae]. [NL. See
   Hepatic. So called in allusion to the shape of the lobed
   leaves or fronds.]
   [1913 Webster]
   1. (Bot.) A genus of pretty spring flowers closely related to
      Anemone; squirrel cup.
      [1913 Webster]

   2. (bot.) Any plant, usually procumbent and mosslike, of the
      cryptogamous class Hepatic[ae]; -- called also scale
      moss and liverwort. See Hepatic[ae], in the
      Supplement.
      [1913 Webster]

WordNet (r) 3.0 (2006):

liverwort
    n 1: any of numerous small green nonvascular plants of the class
         Hepaticopsida growing in wet places and resembling green
         seaweeds or leafy mosses [syn: liverwort, hepatic]