Catathelasma is a genus of fungi in the family Biannulariaceae. Basidiocarps (fruit bodies) are agaricoid, with a conspicuous veil (leaving a double ring on the stem), adnate to decurrent lamellae, and amyloid basidiospores. The genus is separated on DNA characteristics as well as morphology. Species are known from North America, Europe, and Asia and are ectomycorrhizal, forming an association with the living roots of trees.

...