Susana Cunha - I mostly used GBIF data to estimate number of sites (including both georeferenced and not georeferenced occurences), with the exception of countries that were not included in GBIF. Some records are not very recent, e.g last observation in Morrocco was in 1968.
This species was included in a checklist for the Canary islands, but was later changed to Cortinarius variiformis, a similar species (https://www.researchgate.net/profile/Vicente-Escobio-2/publication/264783675_Nuevas_citas_para_el_Catalogo_fungico_de_la_isla_de_Gran_Canaria_Islas_Canarias_III/links/53ef2a890cf2711e0c42ee13/Nuevas-citas-para-el-Catalogo-fungico-de-la-isla-de-Gran-Canaria-Islas-Canarias-III.pdf)
Likely LC (unless we find data on habitat loss triggering the A criterium - unlikely)
Phlegmacium caligatum was originally described as Cortinarius caligatus, but recently moved to the Phlegmacium genus (Liimatainen et al., 2022). Molecular data is available for this species. Cortinarius crustulinus has also been suggested as a possible synonym to Phlegmacium caligatum (Brandrud, 1996; Loizides, 2016), but is currently accepted as a separate species in Species Fungorum.
Phlegmacium caligatum is distributed mostly along the mediterranean region. Based on the number of registered observations, it appears to be more frequent in Spain (including the island of Mallorca), France (including Corsica) and Italy (including Sardinia and Sicily) but it has also been recorded in Portugal, Morocco, Greece, Cyprus, Israel and Lebanon.
This species is currently known from approximately 87 sites: Spain (approximately 51 sites), Italy (13 sites), France (11 sites), Portugal (4 sites, including one further unpublished site from Vasco Fachada in Arrábida), Morocco (2 sites), Israel (1 site), Lebanon (1 site) (GBIF.org, 2023, Brandrud 1996), Cyprus (4 sites) (Loizides, 2016) and Greece (3 sites) (Polemis et al. 2012).
Despite being a relatively conspicuous, P. caligatum may be confused with other similar species, and has been described as fairly rare, at least in some locations (Brandrud 1996). Moreover, assuming evergreen oaks on calcareous soils is the main habitat, habitat availability may be considered low to medium, so a small multiplier for unknown locations can be applied. Population size is therefore estimated between 17400 (87x2x10x10) 87000 (87x2x10x50) mature individuals, assuming 20 mature individuals exist per site (two groups of sporophores) and a 10-50 multiplier for unrecorded localities.
If specimens from Cyprus are not included: Population size is therefore estimated between 16600 (83x2x10x10) and 83000 (83x2x10x50) mature individuals, assuming 20 mature individuals exist per site (two groups of sporophores) and a 10-50 multiplier for unrecorded localities.
Su to Susana: Let’s think 10-20 mature individuals/site (one to two groups of sporophores=functional individuals separated by at least 10 m from each other per site) and 10-100 multiplier (100 maybe too much?) for accounting the unrecorded localities (the species is conspicuous but can be mistaken with similar species; habitat suitability low to medium assuming evergreen oaks on calcareous soils is the main habitat).
Susana to Su: I wrote a minimum and maximum number if we take into account those multipliers - categories through criterion C could vary between VU and LC, depending on population decline.
Found in evergreen sclerophyllous oak forests on calcareous soil, namely in association with Quercus ilex and Q. suber, generally together with Ruscus aculeatus (Brandrud, 1996). It has also been recorded in association with Q. pseudococcifera together with Arbutus unedo (reported by Vasco Fachada), Q. coccifera (Polemis et al. 2012) and Q. rotundifolia, sometimes in conjunction with Cistus (reported in some GBIF.org observations). However, Loizides (2016) reported that specimens in Cyprus were found in association with Cistus salvifolius, sometimes with Pinus sp. and in the absense of Quercus species, and hypothesised that these collections may eventually correspond to an independent species.
Recorded up to 1600m in the Atlas Mountains (Brandrud, 1996).
Some of the presumed main plant hosts for this species, Quercus ilex, Q. rotundifolia and Q. coccifera have been assessed by the IUCN Red List of Threatened Species as Least Concern, though the population of Q. rotundifolia is decreasing (Harvey-Brown, 2017; Rankou, et al. 2017; Jerome and Vazquez, 2018)
Further research is needed to confirm if specimens from Cyprus are conspecific with Phlegmacium caligatum, to better establish distribution and the habitat preferences of Phlegmacium caligatum.