A comparative analysis is presented of the spore morphology, germination pattern, and prothallial development of the sexual phase of seven species in the fern genus Phanerophlebia C. Presl. Gametophyte development was studied from samples grown both on agar and soil. Spores are monolete, ellipsoid, with light brown to dark brown perine; the germination pattern is Vittaria-type and the prothallial development is Aspidium-type in all of the species. The gametangia are of the type typical for leptosporangiate ferns. Gametophytes of all species initially become female, then bisexual. Differences among species include spore germination time (612 days), shape of the gametophytes (spatulatecordiform to cordiformreniform, with smooth to very irregular margins), development time of trichomes (1224 days), and appearance of gametangia (40200 days). Some species develop the first leaves of the sporophytes after 200 days. Results are contrasted with previously published reports on gametophyte development in Arachniodes Blume, Cyrtomium C. Presl, Didymochlaena Desv., Dryopteris Adans, Olfersia Raddi, Polystichum Roth, and Stigmatopteris C. Chr.Key words: Dryopteridaceae, fern gametophyte, Mexico, morphogenesis, Phanerophlebia, sexual phase.
Pollination triggers female gametophyte development in immature Nicotiana tabacum flowers