earthstars

Earthstars are a group of fungi in the genus Geastrum, family Geastraceae. They are saprotrophic, producing distinctive star-shaped fruiting bodies in leaf litter, soil, and decaying wood in woodlands and grasslands worldwide.

The fruiting body begins as a round spore sac at the top of a short stalk. Later, the outer peridium dries and splits into several pointed rays that curve outward, forming a star-like shell that lifts the spore sac above the ground. The spore sac bears a small opening (ostiole) at the apex through which spores escape. The interior gleba is typically brown or dark when mature.

Earthstars fruit in response to moisture; fruiting from late summer to autumn, after rains. They are saprotrophs, feeding on decaying leaves, wood, and organic matter; found in forests, woodland edges, and sometimes lawns with rich soil. They contribute to nutrient cycling.

Geastrum is the main genus, with several species recognized, including Geastrum triphyllum and Geastrum striatum. They can be difficult to distinguish without microscopic study or expert guidance. Spore print color is typically brown.

Earthstars are generally considered inedible due to texture and lack of flavor; some sources caution not to eat raw; they are not known to be toxic but are not commonly consumed. Caution is advised to avoid misidentifying with poisonous lookalikes such as earthballs.