Fungalpedia – Note 669, Seynesiella
Seynesiella G. Arnaud
Citation when using this data: D. S. Marasinghe et al. 2023 (in prep.) – Fungalpedia, Ascomycota.
Index Fungorum, Facesoffungi, MycoBank, GenBank.
Classification: Microthyriaceae, Microthyriales, Incertae sedis, Dothideomycetes, Pezizomycotina, Ascomycota, Fungi
Epiphytic on pinnae of conifers. Superficial mycelium scant, composed of hyaline, branched, septate hyphae or absent. Sexual morph: Thyriothecia superficial, solitary or scattered, shiny, carbonaceous to membraneous, globose, black to dark brown, ostiolate, poorly developed basal layer, opening by a dehiscent stellate. Upper wall comprising neatly arranged radiating cells. Peridium a single stratum, comprising dark-brown cells of textura angularis. Hamathecium comprising of hyaline, filiform, branched, septate, pseudoparaphyses. Asci 8-spored, bitunicate, fissitunicate, clavate to broad cylindrical, long or short pedicellate, ocular chamber not distinct, not staining blue in IKI. Ascospores overlapping biseriate, ellipsoidal to ovate, ends rounded, initially hyaline becoming light brown when mature or greenish hyaline, 1-septum, guttulate or not, the upper cell wider than the lower cell, smooth-walled. Asexual morph: Undetermined (Sivanesan and Shivas 2002; Wu et al. 2011a).
Notes: Arnaud (1918) introduced Seynesiella as a monotypic genus and Müller and von Arx (1962) initially placed it in Venturiaceae. Later, Barr (1987b) transferred this genus from Venturiaceae to Microthyriaceae based on the ostiolate thyriothecia with radially arranged cells, clavate to broad cylindrical asci with ellipsoidal to ovate, 1-septum ascospores. However, the carbonaceous to membranous dark brown to black thyriothecia and light brown ascospores are different from Microthyrium and it resembles Parmulariaceae (Hongsanan et al. 2020a). Therefore, we suggest placing this genus in Microthyriales incertae sedis until it is confirmed with molecular data.
Type species: Seynesiella juniperi (Desm.) G. Arnaud, Annals d’École National d’Agric. de Montpellier, Série 2 16(1–4): 203 (1918) [1917].
Other accepted species: Species Fungorum – search Seynesiella.
References
Arnaud G 1918 – Les Astérinées. Annales de l’école Nationale d’agriculture de Montpellier 16:1.
Barr ME 1987b – Prodromus to class Loculoascomycetes. University of Massachusetts, Amherst.
Müller E, von Arx JA 1962 –Beitr Kryptogamenfl Schweiz 11:1–922.
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