Fungalpedia – Note 634, Uleothyrium
Uleothyrium Petr.
Citation when using this data: D. S. Marasinghe et al. 2023 (in prep.) – Fungalpedia, Ascomycota.
Index Fungorum, Facesoffungi, MycoBank, GenBank, Fig. 1
Classification: Asterinaceae, Asterinales, Dothideomycetidae, Dothideomycetes, Pezizomycotina, Ascomycota, Fungi
Epiphytic on the surface of the leaves appearing as blackened areas. Superficial hyphae densely branched, septate, brown appressoria absent. Sexual morph: Thyriothecia superficial, orbicular, elongate to ellipsoidal, black or brown, opening by a central pore, with dark brown outer ring. Upper wall comprises of two layers neatly arranged brown inner cells and dark brown outer cell layer, branching at the outer rim and develop as hyphae strands. Hamathecium comprises quite numerous, fibrous, strongly mucous pseudoparaphyses. Asci 8-spored, bitunicate, clavate to ellipsoidal, apical region of asci usually with a thick opaque region, apedicellate. Ascospores parallel in the asci, hyaline, elongate, straight or slightly curved, elongate fusoid, 1-septum. Asexual morph: “Septothyrella”, coelomycetous. Pycnidia dimidiate to scutate, densely aggretated, rounded, crusty, with wide pore. Conidiogenous cells cylindrical, flask-shaped, hyaline with brown walls, one-celled, holoblastic. Conidia hyaline, cylindrical to clavate, 1–3-septate (Sivanesan 1984; Hongsanan et al. 2014a).
Notes: Petrak (1929) introduced Uleothyrium and Von Arx and Müller (1975) placed this genus in Asterinaceae. Uleothyrium shares some characters with Asterina in having circular, membraneous, thyriothecia with upper wall composing of radially arranged cells and superficial hyphae (Fig. 1). However, the elongate fusoid, elongate, 1-septum, slightly curved, hyaline ascospores are different from Asterina (Honganan et al. 2014a). The asexual morph Uleothyrium was recorded as Septothyrella and we could not find any illustrations in original literature. Therefore, we suggest to transfer Uleothyrium from Asterinaceae to Asterinales incertae sedis until its placement is confirmed with molecular data.
Type species: Uleothyrium amazonicum Petr., Annls mycol. 27(5/6): 388 (1929).
≡ Septothyrella uleana Syd. & P. Syd., Annls mycol. 14(1/2): 96 (1916).
Other accepted species: Species Fungorum – search Uleothyrium.
Figure 1 – Uleothyrium amazonicum (holotype). a Details of herbarium material. b, c Colonies on substrate. d Ascoma viewed on squash mount. e Upper wall of ascoma. f Surface mycelia. g Hamathecium. h–j Asci. k–p Ascospores. Scale bar: d = 50 μm, e, f, h–j = 20 μm. g, k–p = 10 μm. Adapted from Hongsanan et al. (2014a)
References
Hongsanan S, Li YM, Liu JK et al 2014a – Revision of genera in Asterinales. Fungal Divers 68:1–68.
Sivanesan A 1984 – The bitunicate ascomycetes and their anamorphs. J. Cramer, Vaduz, p 701.
Sydow H, Petrak F 1929 – Fungi costaricensis a cl. Prof Alberto M. Brenes Collecti. Ann Mycologici 27:1–86.
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