• Proposed
  • 2Under Assessment
  • 3Preliminary Assessed
  • 4Assessed
  • 5Published

Tylopilus ammiratii Thiers

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Scientific name
Tylopilus ammiratii
Common names
IUCN Specialist Group
Mushroom, Bracket and Puffball
Assessment status
Proposed by
Noah Siegel
Comments etc.
Noah Siegel

Assessment Notes

Taxonomic notes

Described from a collection made in Shasta County, California, USA (Thiers 1975).

This species should be compared genetically with Tylopilus ‘indecisus’ sensu CA (Siegel & Schwarz 2016) and T. humalis.

Why suggested for a Global Red List Assessment?

Tylopilus ammiratii is a rare bolete with a vinaceous color cap when young that becomes brown with age, white to pallid pores that become buff in age and which stain brown when bruised, and a white, non-reticulate stipe. Currently known from six locations, all in California, USA; mostly associated with Black Oak (Quercus kelloggii).

Until much needed modern taxonomic work has been done on California Tylopilus, I recommend listing this species as Data Deficient (DD).

Geographic range

Currently known from six locations (Siegel et al. 2019); all in California, USA. Four in the Sierra Nevada and Cascade Range foothills, one from the Klamath Range, and one on the San Francisco Peninsula (although this collection more than likely represents Tylopilus ‘indecisus’ sensu CA).

Population and Trends

Rare; currently known from six collections (although some of these records may pertain to other species). Five of the collections are older than 30 years. Although potentially suitable habitat is fairly widespread, more data is needed to identify the factors constituting suitable habitat for this species. In addition, targeted surveys for this species, and revisiting historic populations is needed to assess trends.

Population Trend: Uncertain

Habitat and Ecology

Ectomycorrhizal with hardwoods, likely primarily with Black Oak (Quercus kelloggii). Also reported from under Manzanita (Arctostaphylos spp.) and Madrone (Arbutus menziesii), although these reports may involve other Tylopilus taxa. Fruiting from early fall into winter.


Too little is known regarding this species’ distribution and details of its habitat preferences to properly assess threats.

Conservation Actions

No specific conservation actions are needed with regards to this species.

Research needed

Modern taxonomic work on Tylopilus species in California. Data to assess population trends. Revisiting historic populations to check for presence or absence of this species.

Use and Trade

None known.


Siegel, N., Vellinga, E.C., Schwarz, C., Castellano, M.A. and Ikeda, D. 2019. A Field Guide to the Rare Fungi of California’s National Forests. Bookmobile: Minneapolis, MN. 313 p.

Thiers, H.D. 1975. California Mushrooms—A Field Guide to the Boletes. Hafner Press: New York, NY. 261 p

Country occurrence

Regional Population and Trends

Country Trend Redlisted