Cora was originally
circumscribed by the Swedish "Father of Mycology",
Elias Magnus Fries, in 1825. He included a single species, until then known as
Thelephora pavonia . Until relatively recently,
Cora was thought to contain one species, or was placed into
synonymy with
Dictyonema. Later authors have suggested that this broad, one-species concept was reinforced by reliance on dried herbarium material: traditional revisions often failed to capture field characters such as thallus consistency, lobe arrangement, colour, and substrate, and instead emphasised features such as hymenophore anatomy and basidiospores. Under this approach, foliose basidiolichens were long treated as a single species (
Dictyonema pavonium, later
D. glabratum), with other proposed taxa (including those placed in
Corella) reduced to synonymy.
Cora was recognized as an independent genus separate from
Dictyonema in 2013.
Molecular phylogenetic analysis using
DNA barcoding of the
internal transcribed spacer region has improved the understanding of the diversity of
Cora. In 2016, a landmark study identified and formally described 70 new species, bringing the total number of recognised
Cora species to 189. This represented a dramatic increase from the single species recognized until about a decade prior. The study employed a "turbo-taxonomy" approach, combining international collaboration, rigorous quantitative
phylogenetic methods, and standardised protocols for
phenotype description to efficiently describe and catalog the new species.
Cora species can be distinguished by a combination of morphological, anatomical, and ecogeographical features. This work established
Cora as one of the most species-rich lichen genera, with estimates suggesting the existence of almost 200 species, and about 450 species predicted to exist. In 2022, Dal Forno and coauthors broadened
internal transcribed spacer (ITS)
barcoding by combining newly generated sequences from 62 fresh collections (2016) with 274 historical herbarium specimens (collected 1888–1998), alongside previously available data; the resulting ITS
dataset comprised 1,091 unique samples from 29 countries (1,325 sequences). Using Illumina amplicon sequencing, they recovered ITS sequences from 76.3% (209/274) of the historical specimens and 93.6% (58/62) of the fresh specimens, whereas
Sanger sequencing succeeded for 19% and 58.1%, respectively. Studies using the PhyloKey tool, which employs a technique called
morphology-based
phylogenetic binning, have help to elucidate the diversity within
Cora. Phylogenetic binning involves mapping morphological onto a molecular reference tree and calculating weights for their consistency. This approach has confirmed the identification of species with high accuracy even with incomplete character data, revealing numerous previously unrecognized species. PhyloKey has also facilitated the restudy of
herbarium samples, providing a more comprehensive understanding of the genus's diversity and aiding in the discovery of new species. Dal Forno and coauthors also argued that the historically small number of names in this group partly reflects missing field information: if collectors did not record colour and substrate, those features are difficult to reconstruct from pressed specimens, and small thalli were sometimes interpreted as immature. They also suggested that differences in ecology and morphology were sometimes treated as environmentally induced variation rather than taxonomic evidence, which contributed to the diversity being overlooked in earlier treatments. ==Habitat and distribution==