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 Arthrorhynchus Kolen. MB#337 Wiener Entomologische Monatsschrift 1: 67 ( Kolenati 1857 ) . – Type species: A. diesingii Kolen. Helminthophana Peyr., Sitzungsberichte der Kaiserlichen Akademie der Wissenschaften. Wien . Mathematisch-naturwissenschaftliche Classe. Abteilung 1 68: 250 ( Peyritsch 1873 ) [MB#2262] Brief description Monoecious. Receptacle three-celled. Cell I extending within the host body into a conspicuous non-septate haustorium. Blackened foot absent. Primary appendage free, consisting of several superposed cells. Each of these cells, except the lowermost basal, give rise to four or more antheridia arranged in whorls. The terminal antheridium bears a dorsal spinous process (the original spore apex, sx). Perithecium with 5–6 cells in each vertical row of outer wall cells; the perithecial tip showing four terminal lobes surrounding the ostiole. Remarks This genus consists of 3–6 species depending on the authors ( Majewski 1994b ). We count six species if A. eucampsipodae Thaxt. is separated from A. diesingii Kolenati (Haelewaters et al. 2020) .