Sistotremastrum

Sistotremastrum is a genus of fungi belonging to the order Agaricales, commonly known as the basidiomycetes. These fungi are characterized by their small, often delicate fruiting bodies, which are typically resupinate or effused, meaning they grow flat against a substrate like wood. The hymenium, the spore-bearing surface, is smooth and possesses distinctive microscopic features.

The basidia, the specialized cells that produce spores, are usually clavate or cylindrical and bear four sterigmata. Cystidia, sterile outgrowths found in the hymenium, are a key taxonomic feature for identifying Sistotremastrum species. They are often large, clavate, and thick-walled, sometimes with encrusted apices. The hyphal system is monomitic, meaning it consists of only generative hyphae. Clamp connections are typically present.

Species within Sistotremastrum are saprotrophic, playing a role in the decomposition of woody debris. Their distribution is generally widespread, found in temperate and boreal regions. Identification of Sistotremastrum relies heavily on microscopic examination of its reproductive structures, particularly the unique cystidia. Further research is ongoing to fully understand the phylogenetic relationships and ecological roles of this genus.