Assessment Notes

Justification

Pleurotus albidus is an edible species known from around 70 sites within the Amazon forest in Brazil, Colombia, and Peru, and the southeastern and southern Brazilian Atlantic Forest, with its distribution also stretching into semi-deciduous subtropical forest in Argentina, the humid Chaco in Paraguay, and to Central America and some regions in Mexico and the Caribbean. Despite its apparently wide distribution, this species is found only in well preserved areas. The species is consumed, harvested, and commercialized by indigenous populations, as its use considered safe. It produces conspicuous basidiomata that grow usually gregariously, in various dead woods, always in pristine conditions. Although there is a continuous and high sampling effort in Atlantic Forest areas within northeastern Brazil, the species has never been collected in this region. A reduction of area in the Brazilian Atlantic Forest of around 8% is expected to be met in 30 years. In the Amazon, the P. albidus population is mainly threatened by impacts of climate change, where a reduction of around 14.7% is expected to be met in the same time frame. In Central America and the Mexican regions, it is expected a total reduction of 12.2% in three generations (30 years). Such loss of habitat will also decrease the quality of remaining habitat patches, and so overall an ongoing and future loss of around 19% of suitable habitat is expected. This is particularly concerning as high-quality habitat is a basic reproductive requirement for the species. A matching population reduction is suspected, but it could be higher given its requirement for high-quality habitat, and its harvest and use - the impacts of which require further research, Therefore, it is considered Near Threatened under A3cd+4cd.

---

Geographic range

The species has a wide distribution, but only was found in very well preserved tropical and subtropical areas of the Americas. The species was described as Lentinus albidus by Berkeley (1843) based on material growing on Citrus sp in the state of Minas Gerais State, Brazil. Additional records from Brazil are from the northern to southern parts of the country, with occurrences to the states of Amazonas, Amapá, Minas Gerais, Rio de Janeiro, Santa Catarina, São Paulo, Paraná, Rio Grande do Sul and Roraima (Spegazzini 1889; Pegler 1988, 1997; Meijer 2001, 2006, 2008; Albertó et al. 2002; Sótão et al. 2004; Menolli et al. 2014; Gambato et al. 2016; Sanuma et al. 2016; Castro-Alves et al. 2017; Timm 2018; GBIF 2024).

Other records in South America include in the Argentinian provinces of Buenos Aires, Córdoba, Misiones, Santa Fe and Tucumán; Colombia department of Risaralda; Guyana; Paraguay departments of Distrito Capital and Paraguarí; and Peru Madre de Dios region (Albertó et al. 2002; Lechner et al. 2004, 2005; Lechner and Albertó 2011; Grassi et al. 2016; Kravetz et al. 2018; Flecha-Rivas and Niveiro 2019; GBIF 2024).

In Central America and the Caribbean, the species was recorded from Cuba in Cienfuegos; Costa Rica in San José and Puntarenas provinces; Guatemala from departments of Totonicapán, Chimaltenango and Huehuetenango; Panama; and in Trinidad and Tobago, in St. Augustine (Minter et al. 2001, Albertó et al. 2002, Morales et al. 2010, Guzmán and Piepenbring 2011, Godínez et al. 2018, GBIF 2024).

In North America, Pleurotus albidus was recorded from Mexico in the states of Hidalgo, Morelos, Veracruz and Tabasco (Moreno-Fuentes and Bautista-Nava 2006, Carreño-Ruiz et al. 2013, Sánchez and Royse 2017, Sosa et al. 2019, GBIF 2024). Additional records from Jamaica (GBIF 2024, gbifID 1986823001 and 1986822944; Martinique (GBIF 2024, gbifID 1990616065) and Puerto Rico (GBIF 2024, gbifID 4438677184, 3059018831, 2249240710) don't fit P. albidus and records from the USA need to be confirmed (GBIF 2024, gbifID 1928349328 and 3916165372).

Kumari et al. (2012) reported the occurrence of P. albidus in the state of Himachal Pradesh, northern India, based only on morphological characters; this is the only record of the species outside the Americas and probably does not represent the species.

---

Population and Trends

Pleurotus albidus is a species with medium to high detectability, growing abundantly, usually gregarious, in numerous groups of basidiomata on a wide variety of dead wood. It is known from about 70 sites and more than 120 collections. The species looks well distributed in tropical and subtropical areas of the Americas, being more common in South America, mainly in Brazil and Argentina. In Brazil, the species is found in the Amazon Forest and in the south and southeastern Atlantic Forest. Although there is a continuous and high sampling effort in Atlantic Forest areas in northeastern Brazil, the species has never been collected in this region, and thus it is believed that its distribution does not reach higher latitudes in this biome. Despite its apparently wide distribution, this species is found only in well preserved areas and because of this its reproductive needs are believed to depend on habitats with high ecological integrity, as all known specimens have been found in areas where natural decomposition processes are preserved and human influence is minimal, suggesting that these optimal conditions are crucial for successful reproduction. The species is expected to occur in another 2,500–3,000 sites with on average 36 individuals per site. Therefore, the population size is estimated around 100,000 mature individuals.

The species' habitat is threatened mainly by historical and continuing urbanization in the Atlantic Forest (Tabarelli et al. 2010, Rezende et al. 2018) and climate change impacts in the Amazon (Zhang et al. 2015). In Central America and the Mexican regions where the species has been reported, the main threats are similar to those in other tropical areas, e.g. anthropogenic disturbances and urbanization (Portillo-Quintero and Smith 2018). Considering those threats, it is suspected that the species will suffer a reduction of at least 19% in the next 30 years (three generations), and this decline is likely to be ongoing at the moment. The population decline was suspected in light of extension loss of suitable habitat (Zhang et al., 2015, Silva et al. 2020, Global Forest Watch 2024) and the putative negative influence that habitat degradation has on species occupation in a given environment (Berglund and Jonsson 2005, Haddad et al. 2015), but the impacts of its harvest and use are uncertain and so this suspected figure could be an underestimate.

Population Trend: decreasing

---

Habitat and Ecology

Pleurotus albidus is a saprotrophic species, a wood decomposer that causes white rot. The basidiomata are usually gregarious, growing in numerous groups on a wide variety of dead and native wood (Citrus sp., Sterculia sp., Salix sp., Populus sp., Cordyline sp., Araucaria angustifolia, Ulmus sp., Ocotea porphyria, Bursera simaruba, Heliocarpus donnellsmithii, Lippia umbellata, Mimosa scabrella) and rarely on living trees (registered at the base of Platanus sp. trunk).

The species occurs in a variety of ecoregions, always in a good forest condition of preservation, in tropical montane cloud forest in Guatemala, Amazon and Atlantic Forest in Brazil, semi-deciduous subtropical forest in Argentina and humid Chaco in Paraguay.

According to interviews conducted with people of the Náhuatl ethnic group in Mexico, who consume and sell the species, P. albidus grows from April (when the rains start) to September, and, according to the community, there must be a new moon (crescent) and abundant rain. If only one of the conditions is present, the fungus does not manifest (Moreno-Fuentes and Bautista-Nava 2006). In Guatemala, according to Morales et al. (2010) the species is found in June and July, the period of greatest commercial movement in the edible fungi market in almost the entire country.

---

Threats

The Amazon Forest is essential for maintaining the global climate system (Swann et al. 2015). The changes in the land use and the expansion of the cattle and soy industries in the Amazon have increased deforestation rates (Zhang et al. 2015). Other threats are constant such as fire, illegal gold mining and logging. A number of modelling studies predict that about 50% of the Amazon basin will be replaced by savanna and arid land vegetation by the end of the 21^st century (Zhang et al. 2015).

As well as the Amazon Forest, the Atlantic Forest is also threatened. The Atlantic Forest has been suffering threats and loss of area over time. As a result of the long history of disturbance, most of the remaining Atlantic Forest is immersed in human-modified landscapes, with many small, edge-affected forest remnants (Joly et al. 2014). According to Rezende et al. (2018), there is only 28% of native vegetation cover remaining for the Atlantic Forest biome, including both forest (26%) and non-forest native formations (2%). Habitat loss and fragmentation, logging, fire, hunting, and climate change have caused an alarming loss of biodiversity in the biome. The expansion of urban areas is also an important pressure further reducing the area of the Atlantic Forest (Joly et al. 2014).

In Central America and the Mexican regions where the species has been reported, the mainly threats are similar to those in South America, which reflect the overall threats to tropical forests (Portillo-Quintero and Smith 2018). Considering the annual area loss in the Brazilian Atlantic Forest from 1985-2018 of 0.25% (Silva et al. 2020) and a continuing decline, a reduction of around 8% is expected to be met in 30 years. In the Amazon, the Pleurotus albidus population is mainly threatened by impacts of climate change, where a reduction of around 14% is expected to be met in the same time frame (Zhang et al. 2015). In Central America and the Mexican regions where the species has been reported an annual reduction of 0.4% has taken place from 2001-2022, Considering a continuous declining, it is expected a total reduction of 12% in three generations (30 years) (Global Forest Watch 2024). For these areas, considering the impacts of habitat fragmentation on small patches, there will be additional habitat quality loss (Berglund and Jonsson 2005, Haddad et al. 2015), which can be projected to a loss of around 19% of suitable habitat.

The species is also harvested and consumed, but the direct impact impacts of this on population dynamics are uncertain and require further research.

---

Conservation Actions

The main conservation action to benefit the species population would be the protection of its habitat and its high-quality habitat condition, as a basic reproductive requirement for the species. In Brazil, most specimens were collected in conserved areas, thus large fragments should be a priority to conserve the species as it guarantees habitat quality as well as the creation of new areas.

Pleurotus albidus is an edible species and the collecting and sustainable use of the species is important. P. albidus has been cultivated experimentally in Argentina (Lechner and Albertó 2011) and Brazil (Gambato et al. 2016, Castro-Alves et al. 2017), but research on production is still scarce. The large scale harvest for commercial purposes of the species needs to be better understood regarding negative impacts in its population stability. The immunomodulatory effects of P. albidus has been recognized (Castro-Alves et al. 2017) and other potential health benefits must be further investigated. 

As the outcomes of climate change are among the main threats to the species population and its habitat, ex situ conservation based on in vitro cultures to protect the species genetic diversity.

New samplings are needed to better understand the distribution of the species, mainly in the Atlantic Forest in northeastern Brazil, in the USA, and the Caribbean. Future research should focus on understanding the extent to which habitat quality is a critical factor for the reproductive success of this species, as current evidence suggests that optimal environmental conditions are essential, but this relationship requires further investigation.

---

Use and Trade

The mushrooms of Pleurotus albidus are edible and have been reported to be used by traditional communities in Mexico, Guatemala, and Brazil.

P. albidus is consumed by the Yanomami indigenous people in the Amazon Forest in Brazil (Sanuma et al. 2016). They consume the mushroom roasted in leaves. The species is not cooked in water, nor are salt and pepper used because, according to the indigenous people, the species has a slightly spicy flavour. P. albidus is traded by the Sanöma, part of the Yanomami people who inhabit the Awaris region, in the mountain forests of the extreme northwest of Roraima, Brazil. The Sanöma Mushroom mix that is sold by the Yanomami people may contain more than 10 mushroom species and is a product of the Yanomami agricultural system. Cutler II et al. (2021), using DNA metabarcoding to identify fungal contents of several food products, confirmed the presence of P. albidus in the product made by Yanomami.

P. albidus is also traded in Mexico where it is sold in popular markets, mainly in the central states of the country (Moreno-Fuentes and Bautista-Nava 2006, Guzmán and Piepenbring, 2011). Moreno-Fuentes and Bautista-Nava (2006) reported the sale of the species in the Huejutla market, in Hidalgo, by the Náhuatl ethnic group. P. albidus is used in Mexico to treat high cholesterol levels, high blood pressure and headache. It is also used as diuretic, laxative, and stimulating (Guzmán 2008).

In Guatemala, the species is collected and consumed by the K'iché people and by the peripheral communities of Sierra María Tecún, in Totonicapán (Godínez et al. 2018). Morales et al. (2010) also reports the sale of the species in Comalapa and Tecpán cities, both in Chimaltenango department, in Guatemala.

---

Source and Citation

Menolli Jr, N., Alves-Silva, G. & Drewinski, M. 2024. Pleurotus albidus. The IUCN Red List of Threatened Species 2024: e.T265909436A265909991. .Accessed on 30 October 2024

---

• Country occurrence