Deadly fibrecap

Statema, B. C. P.

Fungus

Deadly fibrecap

Inocybe erubescens

Known today as: A pale fibrecap that bruises red, of spring and summer woods.
Kind: Fungus
Constituents: muscarine
Poisoning: Muscarine poisoning
In other databases: GBIF search · Wikidata search

Revised October 3, 2026: Checked against its sources, each read in full, in part, or in its abstract. Version 1, first published September 25, 2026.

Caution. Poisonous, and has killed.

Deadly fibrecap: what was it used for?

None.

Deadly fibrecap: what does modern science say?

Its muscarine floods the body: sweating, weeping, salivation, a slowed heart. Atropine, from the deadly nightshade, is the antidote (see Deadly nightshade).

Deadly fibrecap: is it poisonous?

Yes, in some form or dose. Poisonous, and has killed. Its poisoning is muscarine poisoning: Fifteen minutes to two hours. Historical description, not medical advice; in a poisoning, call a poison centre.

Pharmacognosy & Toxicology

Constituents

muscarine ChEMBL

Mechanism

Muscarine is a muscarinic agonist that cannot be broken down by the body’s cholinesterase.

Checked against ChEMBL

muscarine: Measured, as the entry says (“a muscarinic agonist”): Muscarinic acetylcholine receptor (rat), Ki 8.3 nM, CHEMBL1133759; Muscarinic acetylcholine receptor M1 (rat), Ki 12 nM, CHEMBL1126214.

Toxic dose

It holds a possibly fatal dose of muscarine; atropine is its antidote.

Syndrome

Muscarine poisoning

Standing

None.

Constituent names open the compound’s record at PubChem, and “ChEMBL” beside a name opens its record at ChEMBL, the European Bioinformatics Institute’s database of bioactive molecules. Where a mechanism line was checked against ChEMBL (ChEMBL 37, read 1 October 2026), the check is shown with the measured value and its source paper, or says plainly that nothing has been measured. Doses are as the references give them, for description only; this is not medical advice. Each source carries the result of its check against Crossref, PubMed, or the authority’s page: see Verification.

Deadly fibrecap: what lore surrounds it?

Taken for the St. George’s mushroom, which grows at the same season.

The edible mushroom it is mistaken for carries a real tradition of its own: St. George’s mushroom takes its name from fruiting around the saint’s day, 23 April, and has seasonal names across Europe, Maipilz in Germany, marzolino in Italy; in the Basque Country it is traditionally eaten with snails on the feast of St. Prudentius. None of this belongs to the poisonous fibrecap except as the reason foragers confuse the two.

Sources

“Calocybe gambosa” (reference article). Read in full · the text read
Wikipedia, “Inosperma erubescens,” en.wikipedia.org (read 2 October 2026). Read in full · the text read
Wikipedia, “Muscarine,” en.wikipedia.org (read 2 October 2026). Read in full · the text read
Wikipedia, “Atropine,” en.wikipedia.org (read 2 October 2026). Read in full · the text read

Verification

Checked

October 1, 2026, and October 3, 2026

Passes

Every sentence read against its sources, in the pass over the remaining 343 entries
The Standing line checked against the authority it names (EMA, WHO, FDA, CITES, Commission E)
Every dated or regulatory claim checked by category across the database
The mechanism read against ChEMBL (ChEMBL 37): curated mechanisms and measured activity
Every source read, in full, in part, or in its abstract, and every sentence checked against what was read (October 3, 2026)

Sources

4 cited: 4 read in full.

Corrections

now "one of the few European mushrooms whose poison has a true antidote," not "the only."

What was checked, how, and what was found is set out on the Verification page. A checked source is one whose record was found; it does not make the entry medical advice.

Cite This Entry

Version 1 · first published September 25, 2026 · last revised October 3, 2026

Chicago: “Deadly fibrecap.” In Materia Medica, edited by B. C. P. Statema. Version 1. The Thinking Press, 2026–. Last modified October 3, 2026. https://thethinkingpress.org/materia-medica/deadly-fibrecap.
MLA: “Deadly fibrecap.” Materia Medica, edited by B. C. P. Statema, version 1, The Thinking Press, 3 Oct. 2026, thethinkingpress.org/materia-medica/deadly-fibrecap. Accessed 8 Oct. 2026.
APA: Deadly fibrecap. (2026, October 3). In B. C. P. Statema (Ed.), Materia medica (Version 1). The Thinking Press. Retrieved October 8, 2026, from https://thethinkingpress.org/materia-medica/deadly-fibrecap

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