Protalic development of Lygodium heterodoxum and Lygodium venustum (Schizaeaceae)

The development of the gametophytes of Lygodium heterodoxum Kunze and Lygod ium venustum Sw. is described on the basis of spores collected in the State s of Veracruz and Sinaloa, Mexico. The germination of the spores is of the Vittaria-type or Lygodium-type. Prothallial development is of the Adiantum- type with transition to Ceratopteris-type. The gametangia are the usual for leptosporangiate ferns. The first leaf of the sporophyte appeared 85 days after spore sowing; it is digitate-flabelliform, with unicellular club shap ed trichomes in margin and both surfaces, and the stomata anomocytic. Unise xual gametophytes (only with antheridia or archegonia) were found in the cu ltures, so the presence of hormonal substances with "antheridogenic effects " is suggested.