Zwackhiomyces khodosovtsevii
Vegetative hyphae not observed. Ascomata perithecioid, semi-immersed in initial states, superficial at maturity, scattered, black, subglobose, (190–)205–220(–270) μm diam. (n=15); ascomatal wall pseudoparenchymatous, dark brown in the outer part, brown in middle, and hyaline in inner part; (14–)16–18(–20) μm wide (n=20), with 5–7 layers of cells; cells rounded in outer parts and ± radially compressed in the inner part, (4.3–)6.8–7.8(–8.8) (n=25) μm wide; granular brown pigments extracellular, turning black-brown in K. Hymenial gel I–, K/I–. Paraphysoids abundant, branched and anastomosing, 1.5–2.5 μm thick. Asci fissitunicate, clavate, (65–)67–70(–74) × (18.0–)19.2–20.4(–22.2) μm (n=15), endoascus I–, BCr–, containing (6–)8 biseriately arranged ascospores. Ascospores ellipsoid, 1-septate, hyaline, smooth to slightly verrucose, markedly constricted at the septum, (21.2–)25.4–29.6(–34.6) × (8.6–)9.2–10.4(–11.6) μm (n=35), upper cell ± rounded, lower cell narrower than the upper on and slightly attenuated, both cells with a few oil droplets; ascospore length/width ratio (1.9–)2.4–3.0(–3.6) (n=35), with distinct halo 2.5–3.0 μm thick in K. Conidiomata not observed.
The new species is known from two localities in the Kherson region. It grows on Verrucaria cf. nigrescens on limestone pebbles in dry steppe habitats.