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

Amanita jacksonii Pomerl.

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Scientific name
Amanita jacksonii
Common names
Jackson's Slender Caesar
American Caesar's Mushroom
Slender Caesar
Eastern Caesar's Amanita
Amanite de Jackson
César fuselé d'Amérique
IUCN Specialist Group
Mushroom, Bracket and Puffball
Assessment status
Proposed by
Khalil T
Comments etc.
Khalil T, Nicolas Schwab

Assessment Notes

Taxonomic notes

Current name - Amanita jacksonii Pomerl., Naturaliste Canadien 111 (3): 329 (1984) [MB#124588]

Basionym - Amanita umbonata Pomerl., Flore des Champignons au Quebec et regions limitrophes: 516 (1980) [MB#124364]

Taxon synonyms- Amanita tullossii Guzmán & Ram.-Guill., Bibliotheca Mycologica 187:33 (2001) [MB#4855191]

Why suggested for a Global Red List Assessment?

This species could be getting mistaken for the Amanita species that produce toxic compounds and as a result, humans could be a larger threat to this species than is currently known.

Geographic range

Population and Trends

Commonly found from Quebec to Mexico. 2,265 observations on iNaturalist. Spread throughout the Eastern United States, Canada, southern Mexico, Guatemala, Honduras, Netherlands, El Salvador, Colombia. The preferred habitat is temperate forests. Ectomycorrhizal fungi so the default generational time period is 50 years. The population trend seems to be unknown, but the fungus seems pretty common throughout its range.

Population Trend: Uncertain

Habitat and Ecology

The trophic mode of this species is mutualistic. The species is mycorrhizal with oak and pine trees, and has been primarily found in pure conifer forests, deciduous woods, cloud forests of pine and oak, and mixed forests. Common in oak and pine forests and fields of the Piedmont area in North Carolina.

Boreal ForestTemperate Forest


Deforestation of oak and pine forests.

Housing & urban areas

Conservation Actions

Conserve forests of oak and pine, old-growth forests. Limit human expansion into wooded areas.

Resource & habitat protection

Research needed

Population data is lacking. Threat data is lacking.

Population size, distribution & trendsThreats

Use and Trade

This species is edible for humans, enjoyed throughout its range, as well as eaten by Eastern gray squirrels.

Food - humanFood - animal


EditNGX. (2020, August 7). Focus on mushrooms: American Caesar, Amanita jacksonii. NGXchange. https://ngxchange.org/focus-on-mushrooms-american-caesar-amanita-jacksonii/

Index Fungorum—Names Record. (n.d.). Retrieved December 3, 2020, from http://www.indexfungorum.org/Names/NamesRecord.asp?RecordID=124588

Mushroom Observer. (n.d.). Retrieved December 3, 2020, from https://mushroomobserver.org/observer/index_observation?by=num_views&q=1YjI6

Mycobank. (n.d.). Retrieved December 3, 2020, from https://www.mycobank.org/page/Simple names search

Observations. (n.d.). INaturalist. Retrieved December 3, 2020, from https://www.inaturalist.org/observations

Search. (n.d.). Retrieved December 3, 2020, from https://www.gbif.org/species/5452395

Umansky, J. (2019, July 28). Amanita jacksonii aka American Caesar’s Mushroom. Larder Delicatessen and Bakery. https://larderdb.com/amanita-jacksonii-aka-american-caesars-mushroom/

van der Nest, M. A., Beirn, L. A., Crouch, J. A., Demers, J. E., de Beer, Z. W., De Vos, L., Gordon, T. R., Moncalvo, J.-M., Naidoo, K., Sanchez-Ramirez, S., Roodt, D., Santana, Q. C., Slinski, S. L., Stata, M., Taerum, S. J., Wilken, P. M., Wilson, A. M., Wingfield, M. J., & Wingfield, B. D. (2014). Draft genomes of Amanita jacksonii, Ceratocystis albifundus, Fusarium circinatum, Huntiella omanensis, Leptographium procerum, Rutstroemia sydowiana, and Sclerotinia echinophila. IMA Fungus, 5(2), 472–486. https://doi.org/10.5598/imafungus.2014.05.02.11

Country occurrence

Regional Population and Trends

Country Trend Redlisted