Kretzschmaria

Kretzschmaria is a genus of fungi belonging to the Ascomycota phylum. These fungi are typically found on decaying wood, often in forest environments. The genus is characterized by its dark, often black, stromata, which are hardened fungal tissues that bear the reproductive structures. The perithecia, which contain the asci and ascospores, are usually embedded within the stroma. Kretzschmaria species are saprotrophic, playing a role in the decomposition of dead plant material.

One of the most well-known species in this genus is Kretzschmaria deusta, formerly known as Hypoxylon deustum. This species is easily recognizable by its effused, carbonaceous stromata that are typically cracked and irregular, often appearing like burnt patches on the wood substrate. The perithecia are visible as small, ostiolate openings on the surface of the stroma. The ascospores are typically dark and elongated. Kretzschmaria deusta can be found on a variety of hardwood species, contributing to the nutrient cycling in forest ecosystems.

The taxonomy of Kretzschmaria has been subject to revision, with molecular phylogenetic studies helping to clarify relationships within the genus and with other related fungal groups. While often overlooked due to their dark coloration and association with decaying wood, Kretzschmaria species are an integral part of forest ecology. Their presence indicates decomposition processes are actively occurring, supporting the broader ecosystem.