The Earthball mushroom, belonging to the genus Scleroderma, is a common fungus that often causes confusion among those interested in wild foraging. Despite its resemblance to certain edible species, Earthballs are not considered food and are classified as poisonous. The entire Scleroderma genus should be avoided because mistaking this fungus for a harmless look-alike can lead to acute illness.
Are Earthballs Poisonous?
Earthball mushrooms are toxic and contain compounds that act as gastrointestinal irritants. Ingesting any part of a mushroom from the Scleroderma genus can trigger a rapid onset of symptoms, including intense nausea, vomiting, and abdominal cramping, often within 15 minutes to a few hours.
The toxicity is primarily due to unidentified irritants, though some species contain compounds like sclerocitrin. While Earthballs are not deadly like some Amanita species, the resulting illness can be significant, sometimes including dizziness, confusion, or temporary visual disruption. Full recovery can take several days, and medical attention should be sought if ingestion is suspected, especially to manage fluid loss.
Key Identification Features
Identifying Earthballs requires close attention to the mushroom’s tough outer skin, known as the peridium. This exterior layer is usually yellowish, ochre, or brownish and features a leathery, warty, or scaly texture. The fruit body is typically spherical or potato-shaped, ranging from four to ten centimeters in diameter.
A Scleroderma specimen lacks a true stem, instead attaching itself directly to the soil via white, thread-like mycelial cords. The most telling feature is the internal tissue, called the gleba, which changes color rapidly as the mushroom matures. When very young, the gleba may appear off-white, but it quickly transitions to a dark, purplish-black mass filled with developing spores. This dark interior often exhibits white flecks or veins, a distinct pattern indicating the Earthball genus.
Distinguishing Earthballs from Edible Puffballs
The most common foraging confusion involves mistaking a poisonous Earthball for an edible puffball from genera such as Lycoperdon or Calvatia. The crucial distinction lies in the appearance of the flesh when the mushroom is cut open vertically. A puffball safe to eat must have a pure, uniform, and solid white interior, resembling cream cheese, with no hint of color or pattern.
In sharp contrast, the Scleroderma Earthball, even when young, shows a tough, thick rind and a gleba that is already beginning to darken. This darkening manifests as a marbled, grayish, or purplish color, often with distinctive white veins. The absolute rule is to discard any specimen that shows coloration other than solid white when sliced in half.
Edible puffballs also have a much softer, thinner skin than the tough, warty peridium of the Earthball. Earthballs release their spores by breaking apart irregularly, whereas true puffballs often develop a small opening to disperse them. The cross-section remains the critical factor: a dark or marbled interior signifies a poisonous Earthball.