Taxonomy of Toxins

Hapalopilus nidulans

investiganda

f. cul.

Hapalopilus nidulans investiganda

investiganda: Owed an investigation. The species is on the Needs Investigation table because a question stands on its published record that the Key cannot read a verdict from: a poisoning reported and no molecule found, a molecule found and no sourced route, a mark in a source list, a molecule known from this one species and not yet confirmed. The name is the stem of its recorded molecule, where the record names one and decides it, then investiganda, and nothing after it while the row is open. Where the record names no molecule the name is investiganda alone, and the gap is deliberate. The Key reads molecules: it puts a molecule in a name only when a record has placed that molecule in the mushroom. A poisoning report is not such a record; it says that harm occurred, not what caused it. The molecule may well exist, and the word states that it is to be found, not a guess at what it will be. The species is not innocuus, because innocuus means that the published record carries no link to a toxic molecule, and this species is on the table because the question of such a link is open; it would be innocuus only once the question is closed in that direction. The species leaves the table, and the word, by a ruling: its molecule registered and read, or its record found to carry no molecule after all. Latin, the gerundive of investigare: to be investigated.

On Needs Investigation, The Complete Table.

GBIF: photographs, names and where it has been found.

Needs Investigation. Why it is here: Polyporic acid (formerly M31) is reported in this species and may be of concern. It was removed from the molecule table on 2026-10-09 because WR had never approved it (it was registered before Rule 3), so the species has no molecule and no verdict. (a published record). What would settle it: William Rubel evaluates whether Polyporic acid harms a person by mouth, eaten raw, at the portion (Rule 3). If he registers it, the molecule and this link return. The link's source, as recorded: Original isolation from this fungus (Stahlschmidt 1877, when named Polyporus nidulans/rutilans); confirmed and quantified up to ~40% dry weight by Kraft et al., Arch. Toxicol. 72 (1998) 711-721, PMID 9879809, and Langer et al. 1992. NAMA review (Beug 2012, McIlvainea) states H. nidulans 'can contain up to 40% polyporic acid by dry weight' and treats it as the type case. Direct chemical detection and quantification.

Cite this pageRubel, William. 2026. “Hapalopilus nidulans.” Taxonomy of Toxins. Last modified 24 October 2026. https://taxonomyoftoxins.com/species/hapalopilus-nidulans/