Earthstar

Geastrum, commonly known as the earthstar, is a genus of basidiomycete fungi that produce distinctive star-shaped fruiting bodies. The outer shell, called the peridium, is initially a single disk that ruptures into four or more radiating arms as the fungus matures, revealing an inner sac, or endoperidium, that contains the spores. When fully developed the Earthstar’s starburst appearance resembles a comet or a firework set against a forest floor or lawn.

These fungi are saprotrophic, feeding on decomposing wood and leaf litter. They are found worldwide, with the largest diversity occurring in temperate deciduous and coniferous forests, grasslands, and even disturbed suburban areas. Many species, such as Geastrum lloydii, Geastrum triplex, and Geastrum ovoidum, can be identified by the size, color, and number of arms, as well as the shape of the spore sac. Spore dispersal is typically triggered by rain; raindrop impacts launch the spores into the air. The spores produce a characteristic white or pale spore print.

The name Earthstar reflects the Greek words for earth (ge) and star (astron), capturing the fungus’s ground‑based, star‑shaped form. While some species are prized by mushroom enthusiasts for their unusual appearance, they are generally considered of little culinary value. In folklore and some herbal traditions, Earthstars have been attributed symbolic meanings, often associated with ancient forest spirits or protective charms. Scientifically, they provide insight into fungal spore dispersal mechanisms and the ecological role of decomposers in terrestrial ecosystems.