Pseudococcomyces Lan Zhuo & C. L. Hou, 2025

Zhuo, Lan, Wang, Hai-Qi, Zhang, Peng, Sui, Xiao-Nan, Guo, Mei-Jun, Wang, Shi-Juan & Hou, Cheng-Lin, 2025, New genera and species of coniferous twig-inhabiting Rhytismatales from China, IMA Fungus 16, pp. e 138790-e 138790 : e138790-

Pseudococcomyces Lan Zhuo & C. L. Hou gen. nov.

Etymology.

Referring to morphologically similar species of Coccomyces .

Diagnosis.

This new genus is similar to Coccomyces , but lacks a basal Covering stroma.

Type.

Pseudococcomyces yunnanensis Lan Zhuo & C. L. Hou , described below.

Sexual morph.

Ascomata on twigs of Larix sp. , erumpent from bark, scattered, round or slightly irregular, surface wrinkled, black (# 000000), opening by radial or irregular splits. In median vertical section, covering stroma well developed. Basal Covering stroma absent. Internal matrix of Covering stroma present, consisting of hyaline, thin-walled, interwoven hyphae. Subhymenium consisting of thin-walled, angular cells. Paraphyses filiform, coiled, interwoven at their tips. Asci clavate, thin-walled, J –, 8 - spored. Ascospores aseptate, filiform, hyaline, covered by a thick gelatinous sheath.

Asexual morph.

Conidiomata and zone lines not seen.

Notes.

Based on the phylogenetic analysis, sequences of Pseudococcomyces form a well-supported clade (MLB = 100 %, MPB = 99 %, PP = 1.00; Clade 8, Fig. 1 ), and appear to be closely related to Stipamyces , but ascomata of Stipamyces are stalked. The ascomata of the type species of the new genus is morphologically similar to ascomata of species of the genus Coccomyces , but the sequences of species in the new genus on the phylogenetic tree are distant from the sequence of the type species of the genus Coccomyces ( Co. tumidus ). Based on morphological and phylogenetic differences, we describe Pseudococcomyces as a new genus.

Figures

Figure 1. Phylogenetic tree derived from maximum likelihood analysis of combined ITS, nrLSU, and mtSSU rDNA sequences of Rhytismatales, using Cudoniella clavus (AFTOL-ID 166) and Pezicula carpinea (KUS-F 51029) as outgroups. Bootstrap support values for ML analysis (MLB) and MP analysis (MPB) greater than 70 % and Bayesian posterior probabilities (PP) greater than 0.95 are given above the nodes. Names of new species and a new combination are written in bold. Species name T – Type species; Species name H – Holotype.