Fungalpedia – Note 662, Arnaudiella
Arnaudiella Kuntze
Citation when using this data: D. S. Marasinghe et al. 2023 (in prep.) – Fungalpedia, Ascomycota.
Index Fungorum, Facesoffungi, MycoBank, GenBank.
Classification: Microthyriaceae, Microthyriales, Dothideomycetidae, Dothideomycetes, Pezizomycotina, Ascomycota, Fungi
Saprobic on leaves or stems appearing as blackened circular spots. Superficial mycelium absent or indistinct. Sexual morph: Thyriothecia circular to subglobose, superficial, solitary, papillate, scattered or gregarious, membranous, or slightly carbonaceous, dark brown to black, lower peridium poorly developed with a black clypeus. Upper wall comprised of parallelly arranged cuboid cells from the central ostiole to the outer rim. Peridium comprising a single sub- stratum of 3–4 layers of compressed brown-walled ellipsoidal cells of textura angularis. Hamathecium composed of hyaline, cellular, pseudoparaphyses. Asci 8-spored, bitunicate, fissitunicate obclavate, short pedicellate, ocular chamber not obvious, not bluing in IKI. Ascospores overlapping uniseriate or biseriate, oval to broad ellipsoidal with rounded ends, brown, 1-septum, smooth-walled. Asexual morph: Undetermined.
Notes: Petrak (1927) established Arnaudiella with the type species A. caronae. This genus was initially placed in Microthyriaceae based on easily detaching circular, ostiolate thyriothecia comprising radially arranged cuboid cells of the upper wall (Wu et al. 2011a). Arnaudiella is morphologically similar to Seynesiella (Swart 1986) in having superficial circular to subglobose, ostiolate, thyriothecia with radially arranged upper wall and 1-septum ascospores. However, Arnaudiella differs from Seynesiella by membranous thyriothecia and brown ascospores, while Seynesiella has a carbonaceous thyriothecia and light brown ascospores. Wu et al. (2011a) restudied the Arnaudiella caronae (PDD 54414) and provided an updated description.
Type species: Arnaudiella caronae (Pass.) Petr., Annls mycol. 25(3/4): 339 (1927).
≡ Seynesia caronae Pass., Atti Reale Accad. Lincei, Rendic., Sér. 4 4(2): 63 (1888).
Other accepted species: Species Fungorum – search Arnaudiella.
References
Swart HJ 1986 – Australian leaf-inhabiting fungi XXII. Microthyrium- like fungi on Eucalyptus. Trans Br Mycol Soc 87:81–91.
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