A new species of true morel from Switzerland: Morchella helvetica , sp. nov.

Morchella helvetica , sp. nov. ( Morchella sect. Distantes ) 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 Morchella helvetica is a sister species to M. eximioides, M. angusticeps , and M. confusa . It can be distinguished by the two phylogenetic markers RNA polymerase II subunit 2 ( RPB2 ) and translation elongation factor-1 alpha (TEF1-α ). In addition, M. helvetica exhibits particular morphological features, notably the presence of pale hairs on the pileus, a mealy stipe, and darkening ridges when aging.