48, see text The Roccellaceae are a family of mostly lichen-forming fungi in the order Arthoniales, established by the French botanist François Fulgis Chevallier in 1826.

Species in the family exhibit various growth forms, including crustose and fruticose (shrub-like) thalli, and diverse reproductive structures.

Roccellaceae species typically have disc-like (apotheciate) or slit-like (lirellate) fruiting bodies, often with distinct blackened (carbonised) margins.

Roccellaceae produce lichen substances from different chemical classes, some of which have been historically important as sources of purple or red dyes like orchil.

They form symbiotic relationships with green algae of the genus Trentepohlia, contributing to their ecological success in diverse habitats, especially coastal and near-coastal environments.

The family was circumscribed by the French botanist François Fulgis Chevallier in his 1826 work Flore Générale des Environs de Paris.

[1] Following standard practice in botanical nomenclature,[6] the name Roccellaceae is derived from the type genus Roccella, with the suffix -aceae denoting its rank as a family.

[1] Its status as a distinct family was firmly established by genetic evidence, first demonstrated in a large-scale phylogenetic study by Damien Ertz and Anders Tehler in 2011.

[10] The family is part of one of the three major evolutionary lines identified within Arthoniales, specifically the lineage that includes Lecanographaceae, Opegraphaceae, Roccellaceae, and Roccellographaceae.

Some synapomorphies for Roccellaceae include the reduction of the proper exciple, the protective layer around the hymenium, (with a reversal in Lecanactis) and the loss of the gelatinous sheath surrounding ascospores.

The reduction of the proper exciple suggests a shared evolutionary trend within the family, possibly related to environmental adaptations or reproductive strategies.

The absence of a gelatinous sheath around ascospores, a feature often associated with spore dispersal and protection, indicates a unique developmental pathway in Roccellaceae compared to related families.

The reversal of the reduced exciple in Lecanactis highlights the complex evolutionary history within the family and demonstrates that even synapomorphies can exhibit exceptions within a monophyletic group.

Tehler's 1990 study was among the first to apply cladistic analysis to relationships within Arthoniales and Roccellaceae, using type species of genera as the end points of the evolutionary tree.

It also highlighted the ecological association of many Roccellaceae species with coastal habitats and suggested multiple origins of the fruticose (shrub-like) habit within the family, with reversals to crustose forms in some lineages.

[11] Molecular phylogenetic studies of Roccellaceae began in the late 1990s, with early work utilising both internal transcribed spacer (ITS) and small subunit ribosomal DNA (SSU rDNA) sequences.

[14] Mazosia Erythrodecton Dichosporidium Enterographa Sigridea Gyrographa Psoronactis Austroroccella Isalonactis Sagenidiopsis Chiodecton Lecanactis ‘Schismatomma’ cf.

umbrinum Schismatomma Diromma Dirina Roccella Pseudoschismatomma Ocellomma Gyronactis Crocellina Vigneronia Roccellina Dendrographa Syncesia Building on these early findings, more recent molecular studies, particularly those using nuclear large subunit ribosomal RNA (LSU) and RNA polymerase II second largest subunit (RPB2) gene sequences, have provided insights into the phylogenetic relationships within Roccellaceae.

[16] These phylogenetic findings have important implications for understanding the evolution of morphological traits within the family, particularly the development of different growth forms.

These molecular phylogenetic studies have thus provided a new framework for understanding the relationships and evolutionary history of Roccellaceae, offering insights that were not evident from morphology alone.

The repeated independent evolution of similar traits in different lineages highlights the adaptive nature of these characters and the need for integrating molecular, morphological, and chemical data in understanding the evolutionary history and classification of this diverse lichen family.

The asci have an apical tholus (thickened inner apex) and narrow ocular chamber (small space at the tip), often with an amyloid ring-structure.

A study of these algae found that photobionts of Roccella species from various European locations, including Spain's Canary Islands and Portugal, form a distinct phylogenetic lineage within a larger group of Trentepohliaceae.

The choice of photobiont leads to radical morphological differences in the lichen thallus, with the Trebouxia-associated form previously recognised as a separate species, "Buellia violaceofusca".

This photobiont flexibility allows L. amylacea to use a wider range of tree hosts and potentially expand its ecological niche and distribution.

Some species, such as Pentagenella fragillima, adapt to extreme environments like the Chilean coast, growing on vertical, south-exposed rock and cliff faces.

Roccellina leptothalla, once thought to be restricted to South America (Brazil), is now also found in the Northern Hemisphere in the Antilles (Martinique and Guadeloupe).

[24] Chiodecton inconspicuum (Data Deficient, 2023) is associated with the Magdalena River, but there is insufficient information about its population, habitat, ecology, and potential threats to assess its conservation status.

[25] Chiodecton subordinatum (Data Deficient, 2023) is known from dry enclaves in Santander Department, but there is insufficient information about its population, habitat, ecology, and potential threats to assess its conservation status.

[22][23][24][25][26] Conservation recommendations for these species include further research on their life history, ecology, and potential additional locations, as well as habitat protection and public awareness campaigns.