Flavoceraceomyces (NOM. PROV.) (Irpicaceae, Basidiomycota), encompassing Ceraceomyces serpens and Ceriporia sulphuricola, and a new resupinate species, F. damiettense, found on Phoenix dactylifera (date palm) trunks in the Nile Delta of Egypt

Abstract

The taxonomy of Polyporales is complicated by the variability in key morphological characters across families and genera, now being gradually resolved through molecular phylogenetic analyses. Here a new resupinate species, Flavoceraceomyces damiettense (NOM. PROV.) found on the decayed trunks of date palm (Phoenix dactylifera) trees in the fruit orchards of the Nile Delta region of Egypt is reported. Multigene phylogenetic analyses based on ITS, LSU, EF1, RPB1 and RPB2 loci place this species in Irpicaceae, and forming a distinct clade with Ceraceomyces serpens and Ceriporia sulphuricolor, which we also incorporate into a new genus Flavoceraceomyces (NOM. PROV.). The honey-yellow basidiomes with white margins and presence of crystal-encrusted hyphae in the hymenium and subiculum are distinctive features of Flavoceraceomyces (NOM. PROV.), despite variability in hymenium morphology and presence of clamp connections and cystidia, as noted for other genera within Irpicacae. F. damiettense is hitherto consistently associated with date palms killed by the red palm weevil Rhynchophorus ferrugineus, a highly damaging and invasive pest, recently spread to the Mediterranean region. F. damiettense causes rapid wood decay by a potentially unusual white-rot mechanism and may play a role in the damage caused by R. ferrugineus.