Taxa named by Othmar Breuss

Placopyrenium is a genus of saxicolous (rock-dwelling), crustose lichens in the family Verrucariaceae.

Involucropyrenium is a genus of lichens in the family Verrucariaceae. It has 10 species. Species in this genus are characterised by their minute, scale-like growth form and distinctive reproductive structures capped with dark sheaths. Most of the ten recognised species were described relatively recently, with several new species added as recently as 2021.

Anthracocarpon is a small fungal genus in the family Verrucariaceae. It is found in Mediterranean regions, the Caribbean, and South America. These lichens form low, crusty patches made up of overlapping scales that grow close to the ground on limestone and other rocky surfaces. The genus is recognized by its distinctive coal-black fruiting bodies, which give it its name—derived from Greek words meaning "coal" and "fruit". Established in 1996, the genus currently includes three species.

Heteroplacidium is a genus of lichen-forming fungi in the family Verrucariaceae. The genus was circumscribed by Austrian lichenologist Othmar Breuss in 1996 with Heteroplacidium imbricatum assigned as the type species. It was proposed as a segregate of Catapyrenium. Other morphologically similar genera are Neocatapyrenium, Placidium, and Scleropyrenium, although molecular phylogenetic analyses indicate that they are independent monophyletic lineages within the Verrucariaceae.

Clavascidium is a genus of lichens in the family Verrucariaceae. The genus was circumscribed in 1996 by Austrian lichenologist Othmar Breuss. Because the type species of the genus, Clavascidium umbrinum, has been shown using molecular phylogenetics to belong to genus Placidium, Cécile Gueidan and colleagues proposed to unite Clavascidium with Placidium in a 2009 publication. Despite this, the genus has been retained in recent publications of fungal classification.