Gomphillaceae

The Gomphillaceae are a family of lichen-forming fungi in the order Graphidales. Species in this family are found mostly in tropical regions. The family underwent a major molecular phylogenetics-led reorganisation in 2023, in which 17 genera were recognised and formally established as new or reinstated.

Taxonomy

The Gomphillaceae has undergone significant taxonomic revision as molecular analysis techniques have improved scientists' understanding of relationships between species. As of 2024, the family includes approximately 440 accepted species, of which 422 are lichenised (form a symbiotic relationship with algae) and 18 are lichenicolous or fungicolous (grow on other lichens or fungi).

The family is particularly diverse in tropical regions, where many species grow on leaves in wet forests. However, some members, particularly in the genus '' Gyalideopsis'', can also be found growing on other surfaces and extend into temperate regions. Recent molecular phylogenetics studies (analysis of DNA sequences to determine evolutionary relationships) have led to a major reorganisation of the family's classification. The research identified 46 distinct genera, including 19 newly recognised lineages. This represents a significant expansion from the previous understanding of the family's diversity. A challenge in classifying members of this family is that only about 27% of known species have had their DNA sequenced. To address this, researchers have used a technique called "phylogenetic binning", which uses physical characteristics to predict where unsequenced species fit within the phylogenetic tree based on their similarities to sequenced relatives. The actual number of species in the family may be significantly higher than currently recognised, possibly exceeding 800 species. This is because detailed examination often reveals that what appears to be a single species may actually be several distinct but closely related species (known as cryptic species).

Recent (2024) sequencing work has filled one of the most persistent gaps in the family tree, with a two-gene phylogeny for the enigmatic ''Paratricharia paradoxa''. The analysis showed that '' Paratricharia'' is sister to '' Caleniopsis'', with the pair forming the earliest branch of a broadened ''Aulaxina'' clade that also contains '' Aulaxina'' and '' Aulaxinella''. This placement corroborates earlier morphology-based predictions and removes ''Paratricharia'' from any close relationship with '' Tricharia'' in the strict sense or the independently evolved "black-setae" lineages '' Microxyphiomyces'' and '' Santricharia''. Because the study emphasised apothecial architecture as a better indicator of deep relationships than the presence of sterile black bristles, several "setae-bearing" genera are now recognised as the result of convergent evolution rather than shared ancestry.

The same paper, together with the suite of genus-level descriptions produced in 2023, confirms that the ''Aulaxina'' clade represents one of at least five major lineages inside Gomphillaceae that have diversified chiefly in tropical leaf-dwelling habitats. These findings dovetail with a 2025 global phylogeny that sampled more than 500 terminals and predicted a total family richness well above 800 species once cryptic diversity is fully resolved. Taken together, the influx of molecular data and the continued use of phenotype-based "binning" for the many still-unsequenced species are progressively stabilising generic concepts, moving the family towards a classification that reflects both genetic relationships and diagnostic morphology.

Description

The family Gomphillaceae is characterized by its crust-like thallus, which is the outer layer of the lichen body. These lichens contain photobionts, which are symbiotic algae that help the lichen to produce food through photosynthesis. The reproductive structures of Gomphillaceae lichens, known as ascomata, can be apothecioid or lirellate in form. Apothecia occur in a few forms, including or to sometimes .

The internal structure of hymenium (the fertile, spore-producing part of the lichen), called the , consists primarily of branched and interwoven . The asci, or spore-producing sacs, are and feature a distinctive apical and ring structure. They can be , oblong, or in shape and do not exhibit any amyloid properties. These asci typically produce eight ascospores, although some may produce fewer, ranging from one to four spores. The ascospores are hyaline (transparent), and have thin walls and distinct . They can be ellipsoid or oblong in shape, and their internal divisions (septa) can be transverse or .

Gomphillaceae lichens also produce , which are asexual reproductive structures. These are mostly , and the conidia are formed as branched hyphae, called diahyphae, within gelatinous masses. The conidia are typically septate, often taking on a or bead-like appearance, and are also hyaline. In terms of secondary chemistry, Gomphillaceae lichens generally lack any notable substances.

Genera

According to a recent (2024) compilation of fungal classification, the Gomphillaceae comprise 44 genera and about 340 species. The following list indicates the genus name, the taxonomic authority, year of publication, and the number of species:
* '' Actinoplaca'' – 2 spp.
* '' Adelphomyces'' – 3 spp.
* ''Aderkomyces'' – 30 spp.
* '' Aplanocalenia'' – 1 sp.
* '' Aptrootidea'' – 6 spp.
* '' Arthotheliopsis'' – 5 spp.
* ''Asterothyrium'' – 12 spp.
* '' Aulaxina'' – 4 spp.
* '' Aulaxinella'' – 3 spp.
* '' Batistomyces'' – 2 spp.
* '' Bezerroplaca'' – 5 spp.
* '' Calenia'' – 20 spp.
* '' Caleniella'' – 2 spp.
* '' Caleniopsis'' – 2 spp.
* '' Cladosterigma'' – 2 spp.
* '' Corticifraga'' – 9 spp.
* ''Diploschistella'' – 5 spp.
* ''Echinoplaca'' – 20 spp.
* '' Ferraroa'' – 1 sp.
* ''Gomphillus'' – 4 spp.
* '' Gyalectidium'' – 40 spp.
* ''Gyalidea'' – 30 spp.
* '' Gyalideopsis'' – 50 spp.
* ''Hippocrepidea'' – 1 sp.
* '' Jamesiella'' – 4 spp.
* '' Lithogyalideopsis'' – 4 spp.
* '' Microxyphiomyces'' – 15 spp.
* '' Monocalenia'' – 1 sp.
* '' Paragyalideopsis'' – 4 spp.
* '' Paratricharia'' – 1 spp.
* '' Phyllogyalidea'' – 2 spp.
* '' Psathyromyces'' – 4 spp.
* '' Pseudocalenia'' – 1 sp.
* '' Psorotheciopsis'' – 7 spp.
* '' Rolueckia'' – 3 spp.
* '' Roselviria'' – 2 spp.
* '' Santricharia'' – 1 sp.
* '' Sipmanidea'' – 2 spp.
* '' Spinomyces'' – 9 spp.
* '' Sporocybomyces'' – 4 spp.
* '' Taitaia'' – 1 spp.
* '' Tricharia'' – ca. 30 spp.
* '' Verruciplaca'' – 2 spp.
* '' Vezdamyces'' – 2 spp.

References

{{Taxonbar, from=Q3110397

Gomphillaceae
Lichen families
Lecanoromycetes families
Taxa described in 1929
Taxa named by Walter Watson (lichenologist)