Habit on leaves of unidentified plant host. Sexual morph: undetermined. Asexual morph: Conidiomata 160–200 µm diam., 150–250 µm high, dark brown to black, pycnidial, usually solitary, immersed to erumpent, globose to subglobose, unilocular, glabrous, thin-walled, ostiolate. Ostiole circular, centrally located. Conidiomatal wall 10–25 µm wide, composed of thin-walled, brown to pale brown cells of textura angularis. Conidiophores arising from the inner wall layer of conidiomata, hyaline, short cylindrical, septate, smooth-walled. Conidiogenous cells 6–14 × 1–3 µm, hyaline, enteroblastic, phialidic, cylindrical to ampulliform, determinate, discrete, smooth-walled. Conidia 14.5–30 × 1.6–3 µm ( = 21 × 2 µm; n = 30), hyaline, subcylindrical, with obtuse apex, and subtruncate base, curved, 1–3-septate, smooth-walled.
Material examined: Thailand, Chiang Mai, on leaves of unidentified plant host, 4 February 2012, N. Tangthirasunun, NTCL038-2F (MFLU 13-0246).
Polyphialoseptoria sp. (MFLU 13-0246) a Herbarium specimen. b–c Appearance of dark brown to black conidiomata on the host. d–e Vertical sections of conidiomata. f Vertical section of peridium. g Ostiole. h–j Conidiophores, conidiogenous cells and developing conidia. k–p Conidia. Scale bars: b = 500 µm, c = 200 µm, d–e = 100 µm, f = 20 µm, g = 50 µm, h–p = 5 µm.
Li WJ, McKenZie EHC, Liu JK, Bhat DJ, Dai DQ, Caporesi E, Tian Q, Maharachcikumbura SSN, Luo ZL, Shang QJ, Zhang JF, Tangthirasunun N, Karunarathna SC, Xu JC, Hyde KD (2020) Taxonomy and phylogeny of hyaline-spored coelomycetes. Fungal Diversity 100: pages279–801.