× Abacopterella × altifrons

Abacopterella altifrons (recorded in the PlantFYI database as × Abacopterella × altifrons) is an intergeneric hybrid fern belonging to the family Thelypteridaceae, commonly known as the marsh fern family or wood fern family in a broad sense. The genus designation with the multiplication sign (×) preceding the name indicates hybrid origin — in botanical nomenclature, × before a genus name denotes that the genus itself is of hybrid derivation between two or more parent genera. In this case, Abacopterella is considered to have arisen through hybridization between distinct genera within Thelypteridaceae, reflecting the occasional occurrence of fertile or sterile intergeneric hybrids in fern lineages, which are well documented within the broader fern families. The species epithet altifrons derives from the Latin altus ('tall' or 'high') and frons ('frond' or 'leaf'), describing a fern with notably tall or large fronds — a character that may distinguish this taxon from related ferns in its natural habitat. Thelypteridaceae comprises terrestrial, rhizomatous ferns that typically grow in moist, shaded environments such as forest understories, stream margins, and wetland edges across tropical and subtropical regions worldwide. The family is characterized by fronds that are usually pinnate to bipinnate, with the veins of adjacent pinnule lobes typically uniting to form a single vein running to the sinus between lobes — a feature that aids in family identification. As a hybrid taxon, × Abacopterella × altifrons may be sterile or of limited reproductive capacity, depending on the chromosomal compatibility of its parent species. The precise natural range of this hybrid fern is likely limited to tropical or subtropical regions where its parental species co-occur.