Zwackhiomacromyces Etayo & van den Boom, Opuscula Philolichenum 13: 70 (2014).
MycoBank number: MB 803963; Index Fungorum number: IF 803963; Facesoffungi number: FoF 08929; 2 morphological species (Species Fungorum 2020), molecular data unavailable.
Type species: Zwackhiomacromyces constrictocarpus Etayo & van den Boom, Opuscula Philolichenum 13: 72 (2014).
Notes: van den Boom and Etayo (2014) established the new genus based on material from the Iberian Peninsula growing on Megaspora verrucosa. The new genus differs from Zwackhiomyces in having lageniform ascomata, with large and granulose papillae, larger asci and ascospores, and normally 3-septate smooth-walled ascospores (van den Boom and Etayo 2014). Later, Etayo and Berger (in Berger and Zimmerman 2016) combined Pyrenidium hyalosporum growing in Placopsis gelida into Zwackhiomacromyces based on ascoma and ascospore characters. This genus tentatively placed in the order Collemopsidiales and Xanthopyreniaceae until molecular data is available.
Species