Pseudothyrium Höhn., in Weese, Mitt. bot. Inst. tech. Hochsch. Wien 4(3): 109 (1927)
Facesoffungi number: FoF 07548
Ascomycota, genera incertae sedis
Saprobic on stems of Polygonatum officinale (Asparagaceae). Sexual morph: undetermined. Asexual morph: Conidiomata dark brown, stromatic, pycnidial, solitary, rarely confluent, subepidermal, immersed, subglobose in section view, unilocular, glabrous. Ostiole indistinct, dehiscence by irregular rupture of the apical wall in the middle part. Conidiomatal wall composed of thick-walled, dark brown cells of textura angularis in the upper and basal part, becoming thin-walled, hyaline cells of textura prismatica towards hymenium. Conidiophores reduced to conidiogenous cells. Conidiogenous cells hyaline, enteroblastic, phialidic, ampulliform, determinate, smooth-walled, and arising from the inner wall layer of basal stroma. Conidia hyaline, cylindrical, acicular, unicellular, smooth-walled, eguttulate (adapted from Sutton 1980).
Type species: Pseudothyrium polygonati (Tassi) Höhn., in Weese, Mitt. bot. Inst. tech. Hochsch. Wien 4(3): 109 (1927)
Notes: Arx (1957a) reduced Pseudothyrium to a synonym of Cylindrosporella Höhn., while Sutton (1980) reinstated Pseudothyrium as a valid genus, accepting a single species in the genus. Pseudothyrium is similar to Erythrogloeum in having stromatic, pycnidial conidiomata and phialidic conidiogenous cells, but it can be distinguished from the latter by cylindrical conidia. There is no molecular data available for this genus. Fresh collections are needed to place it in a natural group.
Distribution: Latvia (Sutton 1980).
Pseudothyrium polygonati (redrawn from Sutton 1980) a Vertical section of conidioma. b Conidiogenous cells and developing conidia. c Conidia.
Li WJ, McKenZie EHC, Liu JK, Bhat DJ, Dai DQ, Caporesi E, Tian Q, Maharachcikumbura SSN, Luo ZL, Shang QJ, Zhang JF, Tangthirasunun N, Karunarathna SC, Xu JC, Hyde KD (2020) Taxonomy and phylogeny of hyaline-spored coelomycetes. Fungal Diversity 100: pages279–801.