whole plant megagametophyte rwalls 2011-03-23T11:32:19Z Megagametophytes in bryophytes only produce egg cells, but do not develop from megaspores, because there is no heterospory in bryophytes. In some pteridophytes, megagametophytes develop from megaspores. In angiosperms, Gnetum, and Weltwischia, the megagametophyte is greatly reduced. The megagametophyte in angiosperms is an embryo sac. female gametophyte (exact) megagametofito (Spanish, exact) PO:0025279 大配偶体 (Japanese, exact) PO_GIT:318 A whole plant in the gametophyte development stage (PO:0028003) that produces only plant egg cells (PO:0020094). plant_anatomy