earthballs

Earthballs is a common name for several species of fungi that produce large, spherical fruiting bodies known as earthballs. They typically range from about 2 to 15 centimeters in diameter. The outer covering, or peridium, is thick and tough and can be brown, purple, or gray. The interior of an immature earthball is white and firm, but as the fruiting body matures the center fills with a spore mass that becomes olive to black and powdery or granular.

Ecology and habitat: Earthballs grow on soil in a variety of habitats, including woodlands, grasslands, and sometimes urban areas. They can appear singly or in small groups. Many earthballs are ectomycorrhizal, forming associations with tree roots, while others are saprotrophic, feeding on decaying organic matter.

Identification and look-alikes: Earthballs can be mistaken for true puffballs when young, but they differ in interior color. Cutting an earthball often reveals a white interior that quickly develops into olive to black rather than remaining uniformly white. The outer skin is typically thicker and tougher than that of edible puffballs. Because color and texture can vary, proper identification is important before any handling or consumption.

Toxicity and safety: Ingesting earthballs can cause gastrointestinal distress, and several species are considered poisonous. Foraging advice generally discourages eating earthballs; if foraging for mushrooms, rely on expert identification and err on the side of caution.

Notable species: Scleroderma citrinum is a widespread earthball in Europe and North America, while Pisolithus tinctorius is common in many regions and is used in forestry inoculants.