The female bias was clearly shown in terms of higher numbers of perichaetia although greater numbers of antheridia than archegonia
occurred within four age classes.
is suggested by double fertilization.
The antheridia developed after the archegonia
, between day 60 and day 70 in most species, with the exception of Blechnum appendiculatum in which they developed after day 80 (Figs.
Sporangia are produced in most ferns on the underside of the leaves, which is again comparable with the position of gametangia on the underside of the prothalli, where archegonia
develop near the growing blastozone (Figs.
But further studies in the biology of the reproduction showed that, from the many cultures made of spores coming from several individuals of the three varieties, it should be accepted that two of the three varieties lack the possibility of forming gametangia (both archegonia
and antheridia), thus the apogamy is totally obligated (Gabriel y Galan 2011, and further personal observations).
Gynoecia on short or elongate shoots, each with 2-5 archegonia
Second, these gametophytes produced archegoniophores that elevated archegonia
above the substrate.
Gametophytes are unisexual, forming either archegonia
(female) or antheridia (male).
emerged in the midrib, between the rhizoids and the meristem.