The basic autonomy of Metasequoia female gametophytes

In France and The Netherlands in Metasequoia glyptostrohoides (Hu and Cheng) only purely female cones are present budding at the end of February. In the absence of any male gametophytic tissue a normal and complete female gametophyte develops. The developments from free nuclear gametophytes to the mature egg cells are presented at light and electron microscopy level. The functional influence of the male gametophyte as a prerequisite for female gametophyte development is questioned and discussed for the different developmental stages as observed in Metasequoia and for other Gymnosperms. In case of Metasequoia, it is suggested that the female gametophyte is basically autonomous.