Koetoimia

Koetoimia is a genus of fungi in the family Sclerodermataceae. These fungi are characterized by their roughly spherical or irregular fruiting bodies, known as basidiocarps, which are typically hypogeous or semi-hypogeous, meaning they grow underground or partially underground. The outer layer of the fruiting body, the peridium, is often thick and leathery, and it may develop cracks or fissures as it matures. Internally, the gleba, which contains the spores, is initially firm and homogeneous, but it breaks down into a powdery mass of dark brown to black spores at maturity.

The species within Koetoimia are generally saprobic, deriving nutrients from decaying organic matter in the soil. They are found in various terrestrial habitats, often associated with forest ecosystems. Identification of Koetoimia species can be challenging and relies on a combination of morphological features, such as peridium texture, gleba characteristics, and microscopic spore morphology. Molecular phylogenetic studies have also been instrumental in clarifying the taxonomic relationships within this genus and its placement within the Sclerodermataceae. The ecological role of Koetoimia is primarily as decomposers, contributing to nutrient cycling in their environments.