Scleroderma citrinum

Scleroderma citrinum, known as the "pigskin poison puffball," "common earthball," or "common earth ball," is the most common species of Earth Ball in the UK and occurs widely in woods, heathland and in short grass from Autumn to Winter. Scleroderma citrinum has two synonyms, Scleroderma aurantium (Vaill.) and Scleroderma vulgare Horn.

Earth Balls are superficially similar to, and considered look-alikes of the edible Puff Balls, but whereas the Puff Ball has a single opening on top through which the spores are dispersed, the Earth Ball just breaks up to release the spores. Moreover, Scleroderma citrinum has much firmer flesh and a dark gleba (interior) much earlier in development than puffballs. Scleroderma citrinum has no stem but is attached to the soil by mycelial cords. The peridium, or outer wall, is thick and firm, usually ochre yellow externally with irregular warts.

The Earth ball may be parasitized by Boletus parasiticus.

Ingestion of scleroderma citrinum can cause gastrointestinal distress in humans and animals, and some individuals may experience lacrimation, rhinitis and rhinorrhea, and conjunctivitis from exposure to its spores.