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Boletus peckii Frost

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Scientific name
Boletus peckii
Common names
IUCN Specialist Group
Mushroom, Bracket and Puffball
Assessment status
Assessment date
IUCN Red List Category
Siegel, N.
Dahlberg, A.

Assessment Notes

The content on this page is fetched from The IUCN Red List of Threatened Species: https://www.iucnredlist.org/species/95383421/95385399


Boletus peckii was, apparently, once a common and widespread ectomycorrhizal species, with many reports prior to 1945. It is now rarely reported, and some of the recent records are questionable. The name has been misapplied to other species and the more modern (post 1970) records need to be examined and evaluated. Until these records are assessed, we have to consider this species status as Data Deficient.

Taxonomic notes

This species was placed into the genus Butyriboletus, based on a genetic sequence from Ron Petersen's 1963 collection from Tennessee, (Zhao et al. 2015). It is likely that this specimen was misidentified. Vizzini had placed it in the genus Caloboletus in 2014 because of its reported bitter taste (Index Fungorum No. 146), Igor Safonov wrote up and sequenced a collection from New Jersey, likely pertaining to B. peckii, which showed affinity to Caloboletus.  Further examination of the Type collection is needed.

Geographic range

Boletus peckii occurs in eastern North America, from central New Hampshire and Vermont, south through the mountains into northern Georgia, west to Indiana. Reports on the gulf coast (Florida into eastern Texas) are questionable, and are being regarded as a distinct species. Reports from Michigan are likely Boletus pseudopeckii.

Population and Trends

Boletus peckii appeared to be very common in the early 1900s with many collections in the Northeast. There are 138 herbarium collections reported on MycoPortal, but only 8 since 1970, and 27 since 1950. Despite extensive collecting by Noah Siegel for many years around the type location, this species has never been seen. The lack of recent herbarium specimens seems to coincide with the timeline of the loss of American Chestnut (Castanea dentata) in the eastern hardwood forest due to the Chestnut Blight, (Cryphonectria parasitica).

Population Trend: unknown

Habitat and Ecology

Boletus peckii is found in hardwood forests of eastern North America. Its preferred ectomycorrhizal hosts are unknown.

Boletus peckii is a mycorrhizal fungus species so it is dependent on living host trees for population viability. This mutually beneficial symbiotic association between fungus and plant host roots conveys numerous critical advantages for plant host survival. Mycorrhizal fungi are essentially the uptake organs for many nutrients i.e., nitrogen, phosphorus, numerous micronutrients (i.e., boron, selenium, copper) and play a major role in uptake of water. The fungus and the plant host do not exist in nature without each other.


Causes for apparent decline of Boletus peckii are uncertain. A correlating factor is the loss of American Chestnut (Castanea dentata); the disappearance of herbarium specimens seems to coincide with the timeline of the loss of American Chestnut in eastern hardwood forest due to the Chestnut Blight, (Cryphonectria parasitica).

Conservation Actions

Conservation needs are unknown. To start with, mycologists need to be aware of the species during fieldwork.
For Boletus peckii, modern collections, a better understanding of the species, and its preferred ecological role are needed.

Source and Citation

Siegel, N. 2019. Boletus peckii. The IUCN Red List of Threatened Species 2019: e.T95383421A95385399. https://dx.doi.org/10.2305/IUCN.UK.2019-1.RLTS.T95383421A95385399.en .Accessed on 3 February 2024

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