Pachystroma

Pachystroma is a genus of fungi in the family Caliciaceae. The genus was first described in 1885 by Franklin Sumner Earle. Pachystroma species are typically found growing on decaying wood, particularly hardwoods. They are characterized by their small, often leathery or brittle apothecia, which are the fruiting bodies of the fungus. The apothecia are usually cup-shaped or disc-shaped and can vary in color from brown to black. The spores of Pachystroma are generally simple, hyaline, and ellipsoid to fusiform.

The type species of the genus is Pachystroma album. Other species that have been described include Pachystroma argyrostroma and Pachystroma compactum. However, taxonomic revisions have led to some species being reclassified into other genera, such as Calicium. The exact number of accepted species within Pachystroma can vary depending on the authority.

Fungal genera like Pachystroma play a role in decomposition within forest ecosystems, breaking down dead organic matter and returning nutrients to the soil. Their ecological significance is primarily related to this saprobic lifestyle. Research into Pachystroma and related genera contributes to our understanding of fungal biodiversity and the complex interactions within woodland environments. Identification of Pachystroma species often relies on microscopic examination of their apothecia and spores, as well as their substrate.