The Gametophytes and Young Sporophytes of Elaphoglossum decursivum (Dryopteridaceae) in Costa Rica

Most studies on ferns focus on the adult sporophytes, overlooking the gametophyte as a potential source of biological information. Herein, field-collected gametophytes and young sporophytes of Elaphoglossum decursivum are described with the aims of providing a more complete understanding on the morphology of this species and additional morphological characteristics for its sectional classification. Gametophytes share the general morphology of most other Elaphoglossum species, but one unusual observation was the presence of minute scales (proscales) on the thallus. Young leaves differ from the glabrous adult leaves by having papillate glandular hairs. These are the first observations of hairs in the glabrous sect. Elaphoglossum. Our study shows that the gametophytes and young sporophytes of E. decursivum have indument characters that are not present in the adult sporophytes, and studying these life stages could potentially be useful in a phylogenetic context.