# Fool’s webcap (Cortinarius orellanus)

**Cortinarius orellanus**

**Known today as.** A tawny webcap of European woods.

Kind: Fungus  
Poisoning: Orellanine poisoning (https://thethinkingpress.org/materia-medica/poisons/orellanine)  
Deadly: yes

> **Deadly.** 

## What was it used for?

None.

## What does modern science say?

The same slow kidney poison as the deadly webcap.

## Pharmacognosy and toxicology

- **orellanine**: 

**Mechanism.** As the deadly webcap.

**Dose.** Not established; the kidney failure comes days after the meal (a median of 8.5 days in one review of cases).

**Standing.** None. Its relative the deadly webcap (*C. rubellus*) poisoned three people near Inverness in 1979 and the author of *The Horse Whisperer* in 2008.

## What lore surrounds it?

A mass poisoning in Poland in the 1950s first revealed how dangerous it is, and orellanine was later isolated from it.

## Sources

- Danel, V. C., Saviuc, P. F., & Garon, D. (2001). Main features of *Cortinarius* spp. poisoning: a literature review. *Toxicon* 39: 1053–1060.
- Wikipedia contributors. “Orellanine.” *Wikipedia, The Free Encyclopedia*. en.wikipedia.org/wiki/Orellanine (read 2 October 2026).
- Wikipedia contributors. “Cortinarius rubellus.” *Wikipedia, The Free Encyclopedia*. en.wikipedia.org/wiki/Cortinarius_rubellus (read 2 October 2026).
- Danel, V. C., et al. (2001). *Toxicon* 39.

---

*Fool’s webcap.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-10-03. The Thinking Press. https://thethinkingpress.org/materia-medica/fools-webcap

Historical description, not medical advice.