Pholiota pelae is only found growing on native substrates in wet, montane habitats in the Hawaiian Islands and all individuals occur in a single subpopulation. The number of mature individuals was estimated to be greater than 2,500 but less than 10,000. Therefore, it is assessed as VU under criterion C2a(ii).

Pholiota peleae has no synonyms. It can be recognized by its macroscopic features as it is the only Pholiota species known from the Hawaiian Islands (Stallman et al. 2022).

The species is only known to occur in native, wet, montane forests in the Hawaiian Islands. Native forests in the islands are contracting, under threat from various factors.

Pholiota peleae is endemic to native, wet, montane forests of the Hawaiian Islands (Hemmes & Desjardin 2002; Horak et al. 1996). ITS sequences of P. peleae (MW018900) do not have high pairwise identity with any sequences in the global metabarcoding datasets UNITE (Abarenkov et al. 2024) or GlobalFungi (Větrovský et al. 2020), providing additional evidence that it is only found in the Hawaiian Islands. While P. peleae is only known from Kauaʻi, West Maui, Molokai, and East Hawaiʻi Island, it may be possibly be found on East Maui, Kohala, Hualalai, and Kaʻū areas of Hawaiʻi Island, and in very small areas of potential habitat on Oʻahu and Lānaʻi.

There are 60 total observations or collections of P. peleae since 1990 (as of April 2026) at 31 unique sites. Pholiota peleae is restricted to a single habitat type in the Hawaiian Islands that is contracting. This habitat contraction will lead to an expected decrease in population for P. peleae in the long-term. In the short term, the increased substrate availability from dead native vegetation is expected to stabilize its population. The number of mature individuals of P. peleae was estimated by taking the 31 sites where the fungus is known to occur and multiplying this by a minimum of 25 and a maximum of 50 additional sites to account for sites with suitable habitat where the fungus may occur but has not been observed. These figures were chosen to balance a potentially low amount of search effort for this relatively small species with the fact that it is macroscopically identifiable and its range is restricted to a single habitat type in the Hawaiian Islands, so it has a small range. Each site was considered to contain two suitable substrates, each containing two mature individuals. Therefore, the population was estimated to be between 3100 to 6200 mature individuals.

All individuals of Pholiota peleae are considered to be in a single subpopulation. Although the confirmed sites on Kauaʻi and Molokai are ~290km apart, the potential habitat on Oʻahu may mean these sites are not so distant. Additionally, ITS sequences from a collection on Kauaʻi and a collection on Hawaiʻi Island—at the extremes of the range—were identical. A population genetics study of a fungus in the Hawaiian Islands with a similar distribution to P. peleae in native, wet, montane forests did not show large genetic differentiation between individuals on different Hawaiian Islands (Keirle et al. 2012).

The species is a saprotroph, producing basidiomata on mosses and various native woody plants (Cibotium spp., Metrosideros polymorpha, Myrsine spp., Psychotria spp.) in wet, montane, native forests in the Hawaiian Islands. Pholiota peleae forms sporocarps throughout the year (Horak et al. 1996; Hemmes & Desjardin 2002).

Many threats exist to forests in the Hawaiian Islands, including wet, montane, native forests. The invasive pathogenic fungi Ceratocystis huliohia and Ceratocystis lukuohia, collectively known as Rapid ‘Ōhi‘a Death (ROD), have been killing large numbers of M. polymorpha trees throughout the islands (Fortini et al. 2019). Metrosideros polymorpha is the dominant tree in these wet, montane forests, and is also a substrate of P. peleae. Additional threats to forests in the Hawaiian Islands include competition from invasive plant species (Gillespie et al. 2008), particularly Psidium cattleianum, and habitat degradation by non-native animals, such as feral pigs (Murphy et al. 2013). Overall, a canopy replacement is occurring in which native tree species are being replaced by non-native tree species (Potter et al. 2023), a process that can be accelerated by M. polymorpha mortality due to ROD.

Conservation actions to preserve or restore wet, montane, native forests in Hawaiʻi, mitigate M. polymorpha mortality from ROD, and slow native to non-native tree species replacement would all benefit P. peleae.

Searching for P. peleae in habitats that may suitable for this fungus, but for where it has not yet been observed or collected, would be helpful to confirm its range. This includes locations in wet, montane, native forests on Oʻahu, Lānaʻi, East Maui, and Kohala, Hualalai, and Kaʻū regions on Hawaiʻi Island. Continuing to document observations of known populations of P. peleae as forests undergo conversion from native-dominated woody species to nonnative-dominated woody species, will provide additional insight on population trends.

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