A novel non-haired Hyaloscyphaceae species, Isthmosporiella glabra sp. nov., in Yunnan Province, China

During a survey of discomycetes in Yunnan, China, one saprobic species of Isthmosporiella was discovered on decayed wood. It is characterized by tiny glabrous and subsessile apothecia, semi-transparent grayish-yellow (fresh) to dark yellow (dried) discs, textura globulosa to angularis cells at the medullary excipulum, textura epidermoidea cells at the ectal excipulum, and multi-branched, septate paraphyses, clavate asci with trapezoidal apices, and ovoid-navicular ascospores. Isthmosporiella glabra is introduced as a new species based on the examination of morphological characteristics and phylogenetic analyses of the combined LSU-ITS dataset. Furthermore, this marks the first sexual morph and the geographic record of Isthmosporiella in China. A comprehensive description, illustration, and phylogenetic analysis are provided here to support its classification.