Introducing Nigrograna italica sp. nov. (Nigrogranaceae) from Corylus avellana and Valsaria tectonae sp. nov. (Valsariaceae) from Tectona grandis

Abstract

Two Dothideomycetes taxa collected from Italy and Thailand were investigated. The first collection, colonizing a dead branch of Corylus avellana in Italy, is identified as Nigrograna italica sp. nov. based on morphology, multi-locus phylogenetic analyses, as well as Genealogical Concordance Phylogenetic Species Recognition analysis (GCPSR). The new taxon, which forms a distinct basal lineage to Nigrograna obliqua, is principally characterised by immersed ascomata with an eccentric to centrally located ostiolar neck and brown hyphae near the ascomatal base and sides, which turn olivaceous or olivaceous brown in KOH. The pseudoparaphyses often branch in the middle or above the asci. The short-pedicellate asci comprise knob-like to furcate bases and a small ocular chamber, and the ascospores are 3-euseptate, smooth, and golden brown to chocolate brown which may become slightly darker in KOH. By utilizing the same methodology, the other new collection, isolated from Tectona grandis in Thailand, is identified as Valsaria tectonae sp. nov. This novel taxon mainly differs from its phylogenetically sister taxon, V. neotropica, in possessing a peridium with two regions, and smaller ascospores with tuberculate to tuberculate-reticulate surface. The work herein provides descriptions, illustrations and notes on these two new species that belong to two genera which accommodate taxa with similar morphology.