Gametophyte
Some gametophytes are subterranean, tuberous elongated with numerous rhizoids; others have vascular tissue
The gametophytes are bisexual, bearing both antheridia and archegonia
The gametophyte typically develops rapidly into a flat, heart-shaped, usually membranous structure (prothallus) that has numerous rhizoids on the lower surface
Both anth and arch develop on the lower surface of the prothallusAntheridia more common among rhizoids; archegonia formed near notch