Alloarthopyrenia Phukhams., Lücking & K.D. Hyde in Hyde et al., Fungal Diversity 80: 122, 131 (2016).
MycoBank number: MB 552236; Index Fungorum number: IF 552236; Facesoffungi number: FoF 02379; one phylogenetically and morphologically defined species (Hyde et al. 2016b).
Saprobic on tree branches in terrestrial, temperate forest habitats. Thallus and photobiont absent. Ascomata solitary, erumpent, carbonaceous, ostiolate, ostiole apical, periphysate. Involucrellum distinct, dark brown. Excipulum prosoplectenchymatous, brownish above, colorless below. Hamathecium comprising 0.5–1 µm wide paraphysoids, hyaline, straight, branched and anastomosing, embedded in a gelatinous matrix. Asci 8-spored, bitunicate, fissitunicate, clavate, short pedicellate, with a non-amyloid ocular chamber. Ascospores irregularly arranged to biseriate, fusiform- ellipsoid to oblong, hyaline, 1-septate, euseptate, with secondary constrictions in each cell, rough-walled, constricted at the septum, with a gelatinous halo. Pycnidia unknown.
Chemistry: no substances detected by TLC.
Type species: Alloarthopyrenia italica Phukhams., Camporesi, Ariyaw. & K.D. Hyde in Hyde et al., Fungal Diversity 80: 122, 135 (2016).
Notes: This monospecific genus was recently introduced for a previously undescribed species growing saprobically on tree branches in Italy. It represents one of now four separate clades in Trypetheliaceae that include members of the collective genus Arthopyrenia, besides Constrictolumina, Macroconstrictolumina (see below) and “Arthopyrenia” aff. minor. Three of these lineages feature ascospores with characteristic secondary constrictions in each of the cells. The discovery of this novel lineage further challenges the systematics of the families Arthopyreniaceae and Naetrocymbaceae the genera Arthopyrenia sensu stricto and Naetrocymbe. Lücking and Nelsen (in Hyde et al. 2013) argued that the type of Arthopyrenia, A. cerasi (Schrad.) A. Massal. differs from the lineages now included in Trypetheliaceae in various anatomical characters, thus likely representing an unrelated lineage; the same argument was made for Naetrocymbe, with the type species N. fuliginea Körb. (Dai et al. in Hyde et al. 2013). However, almost every sequenced member of the collective genera Arthopyrenia and Julella has so far been found to represent a lineage of Trypetheliaceae, and so the fate of Arthopyrenia sensu stricto and Naetrocymbe, whose type species have not yet been sequenced, remains uncertain.