Fungalpedia – Note 721, Trichomerium
Trichomerium. Speg.
Citation when using this data: D. S. Marasinghe et al. 2023 (in prep.) – Fungalpedia, Ascomycota.
Index Fungorum, Facesoffungi, MycoBank, GenBank.
Classification: Trichomeriaceae, Chaetothyriales, Chaetothyriomycetidae, Eurotiomycetes, Pezizomycotina, Ascomycota, Fungi
Epiphytic on the upper surface of leaves. Hyphae, branched, septate, slightly constricted at the septa, pale brown to dark brown, hyphal networks covering the surface of hosts. Sexual morph: Ascomata superficial, solitary to aggregated, subglobose to globose, dark brown to brown, sometimes with ascomatal setae. Setae brown to dark brown or olivaceous, septate or continuous, erect, straight or curved. Peridium two layered, the outer layer of brown to dark brown cells of textura prismatica, the inner layer composed of pale brown to hyaline flattened cells. Hamathecium lack paraphyses. Asci 8-spored, bitunicate, ellipsoidal to cylindrical, clavate, short pedicellate or sessile, ocular chamber present. Ascospores overlapping 2-seriate, hyaline, fusoid, rounded at the ends, 2–3-septate, guttulate, with or without a mucilaginous sheath. Asexual morph: Hyphomycetous. Conidiophores reduced to conidiogenous cells, conidia arising directly from hyphae. Conidia solitary, hyaline to pale brown, or grayish, giving rise to 3–4 lateral arms from a central cell. Conidial arms subcylindrical, tapering to the apex, with rounded ends, pale brown to grayish, 2–5-septate, not constricted or slightly constricted, darker at the septa, smooth-walled.
Notes: Spegazzini (1918) introduced Trichomerium with the type species of T. coffeicolum. It was initially placed in Capnodiaceae and Triposporiopsidaceae and later transferred into the Chaetothyriaceae based on sessile ascomata and trans-septate hyaline ascospores (Batista and Ciferri 1963a; Sun et al. 2020). This is the only sexual genus and it is characterized by superficial, setiferous ascomata with loosely interwoven mycelium, with bitunicate asci and hyaline and septate, hyaline ascospores (Spegazzini 1918; Chomnunti et al. 2012b; Hongsanan et al. 2016b). Tripospermum-like conidia are recorded as the asexual morph of Trichomerium gloeosporum (Hongsanan et al. 2016b). Species of Trichomerium are also referred to as sooty molds based on their blackened hyphal mat (Chomnunti et al. 2012a, b, 2014). However, this genus differs from genera in Capnodiaceae and Chaetothyriaceae in having an apical ascal ring, ascospores with or without sheaths and in their septation (Chomnunti et al. 2012a, b, 2014). Sun et al. (2020) reported some rock-inhabiting slow-growing Trichomerium species (T. leigongense, T. lapideum, T. flexuosumgure and
T. cicatricatufrom) from China.
Type species: Trichomerium coffeicola (Puttemans) Speg., Physis, Rev. Soc. Arg. Cienc. Nat. 4(no. 17): 284 (1918)
Other accepted species: Species Fungorum – search Trichomerium .
References
Batista AC, Ciferri R 1963a – Capnodiales. Saccardoa 2:1–298.
Chomnunti P, Hongsanan S, Aguirre-Hudson B et al 2014 – The sooty moulds. Fungal Divers 66:1–36.
Spegazzini CL 1918 – Notas micológicas. Physics 4:281–329.
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