Visomaceae

Visomaceae is a small, poorly understood family of ascomycetous fungi described to include certain lichen-forming taxa that could not be satisfactorily accommodated within earlier families. Its precise circumscription has varied through taxonomic revisions, and molecular phylogenetic studies have not yet produced a stable, universally accepted placement. As a result, the family remains conservative in size and composition in contemporary classifications.

Ecology and morphology within Visomaceae are largely documented through their lichenized lifestyle. Members form symbiotic associations with green algae or cyanobacteria, producing crustose to squamulose thalli that inhabit a range of substrates, including bark, rock, and soil. Collecting and identifying species typically rely on a combination of field characteristics and microscopic features, but detailed, species-level information is limited for many taxa in this group.

Distribution is broadly described as cosmopolitan, with recorded occurrences from multiple continents, though regional sampling gaps mean that the true diversity and range are not fully known. Many records come from temperate to tropical environments, reflecting where lichen survey work has been conducted.

Genera and species within Visomaceae are subject to ongoing revision as new molecular data become available. The status of the family and the exact boundaries between its constituent taxa may change with future phylogenetic studies.

See also: Fungal taxonomy, Lichenology, List of fungal families.

References to Visomaceae appear in standard fungal nomenclature databases such as Index Fungorum and MycoBank, and in reviews addressing the systematics of lichen-forming fungi.