About spirals and pores: <i> Xylariaceae</i> with remarkable germ loci

Based on phylogenetic analyses of a multi-gene matrix of nuITS-LSU rDNA, <i>RPB2</i> and <i>TUB2</i> sequences and morphology, xylariaceous species with uni- to pauciperitheciate stromata and ascospores having a spirally coiling (helicoid) germ slit are revised and reclassified, including detailed descriptions and illustrations. The genus <i>Helicogermslita</i> is redefined and restricted to seven species with massive, erumpent, clypeus-like carbonaceous stromata, and <i>Rosellinia somala</i> is combined in <i>Helicogermslita</i>. Within the core <i>Xylariaceae</i>, the poorly known <i>Leptomassaria simplex</i> is shown to be closely related to <i>Anthostoma insidiosum</i>, for which the new genus <i>Oligostoma</i> is established, and <i>Anthostoma rhenanum</i> is demonstrated to be synonymous with <i>O. insidiosum</i>. The new genus <i>Albicollum</i>, characterised by immersed ascomata and a collar of white pseudostromatic tissues surrounding the ostioles, is established for <i>Amphisphaeria canicollis</i>, <i>Anthostoma chionostomum</i>, <i>Sordaria</i> (= <i>Helicogermslita</i>) <i>fleischhakii</i> and <i>Anthostoma vincensii. Anthostoma ostropoides</i> is synomymised with <i>Albicollum canicolle</i>, and <i>Al. berberidicola</i>, <i>Al. longisporum</i> and <i>Al. novomexicanum</i> are described as new species. <i>Rosellinia</i> (= <i>Helicogermslita</i>) <i>gaudefroyi</i> is transferred to the new genus <i>Spiririma. Anthostoma amoenum</i> and <i>Euepixylon udum</i>, both with a poroid germ locus, are shown to be only distantly related, and <i>An. amoenum</i> is reclassified within the asexual genus <i>Digitodochium</i>. Based on phylogeny, the genus <i>Euepixylon</i> is treated as a synonym of <i>Nemania</i>. A new species, <i>Nemania ethancrensonii</i>, which is closely related to the two formerly accepted <i>Euepixylon</i> species (<i>E. sphaeriostomum</i>, <i>E. udum</i>) but strongly deviates from the morphological concept of <i>Euepixylon</i> and <i>Nemania</i>, is described from the eastern USA. The genera <i>Anthostomelloides</i>, <i>Clypeosphaeria</i>, <i>Digitodochium</i>, <i>Emarcaea</i>, <i>Induratia</i>, <i>Linosporopsis</i>, <i>Magnostiolata</i>, <i>Occultitheca</i> and <i>Spiririma</i> are revealed to form a morphologically heterogeneous lineage in a basal position of <i>Xylariaceae. Anthostoma vincensii</i>, <i>Quaternaria simplex</i> and <i>Rosellinia gaudefroyi</i> are lectotypified, and <i>Amphisphaeria canicollis</i>, <i>Anthostoma amoenum</i>, <i>An. rhenanum</i>, <i>An. vincensii</i>, <i>Quaternaria simplex</i>, <i>Rosellinia gaudefroyi</i> and <i>Valsa insidiosa</i> are epitypified. Keys to uni- to pauciperitheciate xylariaceous genera with sigmoid to helicoid germ slits and to species of <i>Albicollum</i> are provided. <b>Citation</b>: Voglmayr H, Tello S, Jaklitsch WM, et al. 2022. About spirals and pores: Xylariaceae with remarkable germ loci. Persoonia 49: 58-98. https://doi.org/10.3767/persoonia.2022.49.02.