By Baral H.-O., Bemmann M.
Vol. 5 (4) – 20 October 2013
Abstract: Hymenoscyphus serotinus is a rather well-known and common species which, in its restricted sense, was so far recorded only within Europe, where it fruits exclusively in late autumn and early winter on externally blackened wood of twigs and thin branches of Fagus. Despite its rather characteristic, long and slender, curved (comma-shaped) ascospores, the species was not rarely confused in the past with other European lignicolous taxa: either with H. calyculus, from which it was thought to be insufficiently separated, or with an undescribed species that likewise fruits in late autumn on blackened wood though of Carpinus, and is here described as a new species, H. lepismoides. This differs from H. serotinus in longer and wider, straighter spores, which are provided by prominent terminal setulae, and also in the absence of croziers at the ascus base. Apart from this and some other misinterpretations, Hymenoscyphus serotinus was considered by various authors as a foliicolous taxon, mainly outside Europe. One of these records, on unidentified skeletonized leaves from Jilin (China), was reinvestigated in the present study and considered to be related to, though not conspecific with, H. vacini, a European species confined to skeletonized leaves of Acer. The identity of this and other extra-European records remains to be resolved by future studies