Venturioscypha nigropila (Hyphodiscaceae, Helotiales) – a new genus and species from xeric Pinus bark

Abstract

A new genus and species, Venturioscypha nigropila, is proposed for a minute inoperculate discomycete with long, cylindrical, partly flexuous, dark blackish-brown, smooth, finally thick-walled hairs. It has been collected repeatedly in Europe on dead, corticated branches of Pinus spp. attached to living or recently dead trees. At first glance the species resembles members of Pirottaea (Pyrenopezizaceae), but the relationship is shown by molecular phylogenetics to be close to Hyphodiscus, Hyphopeziza, Fuscolachnum, and Venturiocistella (Hyphodiscaceae). These genera differ in having hairs with more or less conspicuous warts, in Hyphopeziza also with glassy solidifications, and Venturiocistella in having in addition long, stiff, thick-walled, apically acute, dark brown hairs, which are warted in their lower part. The hair wall of Venturioscypha appears superficially smooth, but the surface is inconspicuously pitted as viewed under light microscopy. Venturioscypha is unique in Hyphodiscaceae by its peculiar hairs, inamyloid asci with a thin apical wall that ruptures irregularly by a terminal split at spore discharge, spores with a delicate sheath, and apothecial proliferation.