Gametophytic phase of the fern Llavea cordifolia (Pteridaceae)

The development and sexual phase characteristics of Llavea cordifolia, a ge nus that is monotypic to Mexico, Guatemala and Costa Rica. The spores were collected from Veracruz and Puebla, the culture was in vitro on the basis o f gametophyte population growing in petri dishes. Spore germination is of t he Vittaria-type, resulting in a uniseriate gametophytic filament of four c ells. Prothallial development is of the Adiantum-type. The protallus is cor date-spatulate to cordate and reaches sexual maturity in 60-160 days. The g ametangia are of the common leptosporangiate-type.