# Common earthball (Scleroderma citrinum)

**Scleroderma citrinum**

**Known today as.** A hard, yellow-brown ball with a black interior, of acid woodland.

Kind: Fungus  
Poisoning: Gastrointestinal irritants (https://thethinkingpress.org/materia-medica/poisons/gastrointestinal)  
Toxic: yes

> **Caution.** Poisonous.

## What was it used for?

Put into foie gras, dishonestly, to pass for truffle.

## What does modern science say?

Eaten, it brings vomiting, stomach pain, sweating, and faintness, sometimes within half an hour; its spores can inflame the eyes and nose.

## Pharmacognosy and toxicology

- **sclerocitrin**: 
- **unidentified gastrointestinal irritant**: 

**Mechanism.** Eaten in quantity it gives vomiting and diarrhoea, and its spores can inflame the eyes and nose; the toxin is not identified.

**Dose.** Toxic in large amounts, harmless in small, by one account.

**Standing.** Poisonous; once used in truffle fraud.

## What lore surrounds it?

Once an adulterant of truffle.

Sliced across, the young earthball is black marbled with white, a little like truffle, and smells of metal; dishonest dealers passed it off as truffle in foie gras, and the beginner mistakes it for a puffball, which is softer.

## Sources

- Wikipedia (de), “Dickschaliger Kartoffelbovist,” de.wikipedia.org (read 2 October 2026).
- Wikipédia, “Scléroderme commun,” fr.wikipedia.org (read 2 October 2026).

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*Common earthball.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-10-03. The Thinking Press. https://thethinkingpress.org/materia-medica/common-earthball

Historical description, not medical advice.