The Collaborative International Dictionary of English v.0.48:

Bryopsida \Bryopsida\ n.
   the class of plants comprising the true mosses, having leafy
   rather than thalloid gametophytes; it comprises the orders
   Andreaeales; Bryales; Dicranales; Eubryales; and
   Sphagnales.

   Syn: class Bryopsida, Musci, class Musci.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Bryopsida
    n 1: true mosses: bryophytes having leafy rather than thalloid
         gametophytes: comprises orders Andreaeales; Bryales;
         Dicranales; Eubryales; Sphagnales [syn: Bryopsida, class
         Bryopsida, Musci, class Musci]