Fungalpedia – Note 710, Chaetothyrium
Chaetothyrium. Speg.
Citation when using this data: D. S. Marasinghe et al. 2023 (in prep.) – Fungalpedia, Ascomycota.
Index Fungorum, Facesoffungi, MycoBank, GenBank., Figs 1,2
Classification: Chaetothyriaceae, Chaetothyriales, Chaetothyriomycetidae, Eurotiomycetes, Pezizomycotina, Ascomycota, Fungi
Colonies epiphyllous or hypophyllous on surface of leaves appearing as black dots. Sexual morph: Ascomata solitary or clustered, dimidiate, brown to dark brown, superficial, subglobose to globose, attached to a shorter mycelial pellicle, lacking a distinct ostiole, cupulate on drying, ostioles or papilla not apparent. Ascomatal setae scattered, dark brown at base, brownish at the tip, erect. Peridium multi-layered, pseudoparenchymatous, comprising pigmented, thick-walled cells of textura angularis, with inner layer thinner, flattened, lightly pigmented to hyaline, thin-walled cells. Hamathecium lacking paraphyses. Asci 8-spored, bitunicate, cylindrical clavate to sub-obclavate or clavate to ellipsoid, usually short pedicellate, with an ocular chamber. Ascospores 2–3-seriate, oblong to ellipsoidal, obovoid, septate or muriform, hyaline, smooth or thick-walled. Asexual morph: Coelomycetous and hyphomycetous.
Notes: Spegazzini (1888) introduced Chaetothyrium to accommodate species with ascomatal setae. This genus is characterized by superficial ascomata with setae, lacking paraphyses, clavate to ellipsoid, hyaline, bitunicate, 8-spored asci, with oblong to ellipsoidal, septate or muriform, hyaline ascospores. Species of this genus are also regarded as similar in habit and ecology to capnodiaceous sooty moulds (Chomnunti et al. 2012a; Tian et al. 2021). Chomnunti et al. (2012a) provided the first sequence data (LSU and ITS) for C. bischofiicola and confirmed the placement of Chaetothyrium in Chaetothyriaceae (Chaetothyriales, Eurotiomycetes). Species of Chaetothyrium are morphologically similar to Treubiomyces and Limacinula in having globose, aparaphysate, setose ascomata and muriform hyaline ascospores However, both genera differ from Chaetothyrium in having periphysate distinct ostioles, while the ostioles of Chaetothyrium are not distinct or well-developed. Merismella has been reported as the anamorph of Chaetothyrium (Hofmann and Piepenbring 2006) and it has not yet been formally synonymized under Chaetothyrium (Tian et al. 2021). The taxon is characterized by dimidiate conidiomata, hyaline, with elongated filiform branches and septate conidia liberated in dense bundles (Hofmann and Piepenbring 2006) The recommended loci for this genus are LSU and ITS. According to our phylogenetic analysis, Chaetothyrium showed polyphyletic placement within the Chaetothyriaceae clade and needs more sequence data from new collections for a better understanding of this genus.
Type species: Chaetothyrium guaraniticum Speg., Anal. Soc.cient. argent. 26(1): 46 (1888)
Other accepted species: Species Fungorum – search Chaetothyrium.
Figures 1 – Chaeotothyrium sp. (Material examined: Thai- land, Chiang Mai (Mushroom Research Center), on dead leaves of Fagales, 20 June 2021, Diana Sandamali, DMRC 21–003). a, b Ascomata on the leaf surface. c Section through ascoma. d Peridium. e Ascomal setae. f Arrangement of asci. g–i Asci. j Ascospore. Scale bars: c = 50 µm, d, e, j = 10 µm, f–i = 20 µm
Figures 2 – Euceramia palmicola (Type 4572, holotype, redrawn from Batista and Ciferri 1962). a Ascus. b Ascospores. c Vertical section of ascoma. Scale bars: a, b = 10 μm
References
Spegazzini C 1888 – Pugillus II. Anales de la Sociedad Cientifica Argentina 26:5–74.
Entry by
Diana Sandamali Marasinghe, Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai, 57100, Thailand School of Science, Mae Fah Luang University, Chiang Rai, 57100, Thailand, Mushroom Research Foundation, 128 M.3 Ban Pa Deng T. Pa Pae, A. Mae Taeng, Chiang Mai, 50150, Thailand
Published online 29 August 2023