Collemopsidium kostikovii sp. nov. (Collemopsidales, Xanthopyrenaceae), a new algicolous fungus on terricolous Nostoc crust from Ukraine

Abstract

Collemopsidium kostikovii Khodos. & Darmostuk sp. nov. (Collemopsidales, Xanthopyrenaceae) is described as a new for science species of algicolous fungi. The new species is characterized by pseudothecia fully immersed in algal crust, (80–)90–170(–200) μm wide, not widening ostiole, 10–20 μm diam., 8-spored asci and 1-septate hyaline ascospores, (14.8–)16– 19.6(–23) × (6.3–)6.4–7.8(–9.0) μm. It is morphologically similar to C. iocarpum, but differs by its not widening ostiole and association with terricolous cyanobacterial crust with dominant Nostoc muscorum.