Phacidium innumerum (Massee) Crous, in Crous, et al., Stud. Mycol. 94: 223 (2019)
≡ Ceuthospora innumera Massee, Bull. Misc. Inf., Kew: 182 (1899)
Saprobic on dead leaves of Eucalyptus sp. (Myrtaceae). Sexual morph: undetermined. Asexual morph: Conidiomata 340–430 µm diam., 200–300 µm high, brown to black, stromatic, pycnidial, amphigenous but predominantly hypophyllous, solitary to gregarious, occasionally confluent, deeply immersed with only the red-brown neck of the collection chamber extending above the ruptured host tissue, globose to subglobose or ellipsoid, multilocular, thick-walled, glabrous, ostiolate. Ostiole 140–220 × 88–150 µm, oval or circular, centric or acentric, opening into the base of the locule, not associated with furfuraceous cells in the area of dehiscence. Conidiomata wall 15–30 µm wide, composed of an outer textura angularis with thick-walled, brown to dark brown cells near the ostiole, and an inner textura prismatica gradually merging with textura angularis with thick-walled, hyaline to brown cells at basal and lateral part. Conidiophores reduced to conidiogenous cells or sparsely septate and branched at the base, hyaline, arising from the innermost wall layer of conidiomata. Conidiogenous cells 6–20 × 1–4 µm, hyaline, enteroblastic, ampulliform to subcylindrical with minute periclinal thickenings. Conidia 15–22 × 2.7–4 µm (= 19 × 3 µm; n = 30), hyaline, subcylindrical, broad blunt or rounded at the base, attenuated towards at the apex, aseptate, smooth-walled, bearing a funnel-shaped, mucoid apical appendage.
Material examined: Tasmania, on dead leaves of Eucalyptus sp. (Myrtaceae), Rodway (K(M) 190756, holotype).
Phacidium innumera (K(M) 190756, holotype) a, b Herbarium package and specimen. c Vertical section of conidiomata. d, e Appearance of brown to black conidiomata on the host. f Horizontal view of the locules. g Section of peridium. h, i Conidiophores, conidiogenous cells and developing conidia. j–o Conidia. Scale bars c–d = 100 µm, e = 500 µm, f = 200 µm, g–i = 20 µm, j–o = 10 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.