Laboulbeniomycetes (Fungi, Ascomycota) of Denmark Author Santamaria, Sergi Unitat de Botànica, Departament de Biologia Animal, de Biologia Vegetal i d’Ecologia, Facultat de Biociències, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès (Barcelona), Spain. sergi.santamaria@uab.cat Author Pedersen, Jan Natural History Museum of Denmark (Zoological Museum), University of Copenhagen, Universitetsparken 15, 2100 København Ø, Denmark. japedersen@snm.ku.dk text European Journal of Taxonomy 2021 2021-11-26 781 1 425 http://dx.doi.org/10.5852/ejt.2021.781.1583 journal article 10.5852/ejt.2021.781.1583 2118-9773 5828924 Genus Rossiomyces R.K.Benj. MB#28566 Aliso 19: 132 ( Benjamin 2001 ) . – Type species: R. falcatus (T.Majewski) R.K.Benj. (by monotypy) Brief description Monoecious. Receptacle three-celled. Primary appendage free, consisting of three superposed cells, where the median and upper cells give rise to antheridia, with a spinous process on the upper cell ( Fig. 55B , sx). Perithecium with five cells in each vertical row of outer wall cells; showing apical conspicuous prominences. Remarks Monotypic. Benjamin (2001) reviewed and narrowed the limits of the genus Autophagomyces , erecting the new genus Rossiomyces based on Autophagomyces falcatus T.Majewski , with a combination of the following seven characteristics: (1) the structure of primary appendage (see brief description above), (2) the spinous process formed by the original spore, (3) cells I and II separated by a strongly oblique septum, (4) cells III and II separated by a strongly oblique septum, the first in contact with cell I, (5) the simple or bifurcate trichogyne, (6) the small remnant of trichogyne, and (7) the five tiered perithecial outer wall. Waiting for the discovery of additional species, it is currently difficult to delimit specific characters from generic ones.