A new species of true morel from Switzerland: <i>Morchella helvetica</i> , sp. nov

<i>Morchella helvetica</i>, sp. nov. (<i>Morchella</i> sect. <i>Distantes</i>) is a new species of true morels discovered in Switzerland. It is formally described in the present study using an integrative approach based on micro- and macromorphological characteristics, multilocus phylogenetics, and a brief description of its habitat. Molecular analyses clearly indicated that <i>Morchella helvetica</i> is a sister species to <i>M. eximioides, M. angusticeps</i>, and <i>M. confusa</i>. It can be distinguished by the two phylogenetic markers RNA polymerase II subunit 2 (<i>RPB2</i>) and translation elongation factor-1 alpha <i>(TEF1-α</i>). In addition, <i>M. helvetica</i> exhibits particular morphological features, notably the presence of pale hairs on the pileus, a mealy stipe, and darkening ridges when aging.