Phacidiella P. Karst., Hedwigia 23(6): 85 (1884)
Faceoffungi number: FoF 07480
Lecanoromycetes, Ostropomycetidae, Ostropales, genera incertae sedis
Saprobic on the host plants, such as Artemisia vulgaris (Asteraceae), Asperula asperne (Rubiaceae), Eucalyptus sp. (Myrtaceae), Podocarpus latifolius (Podocarpaceae), Salix caprea, S. viminalis (Salicaceae) and Vitis vinifera (Vitaceae) (Sutton 1980; Purohit and Chawla 1989; Crous et al. 2007, 2014d). Sexual morph: undetermined. Asexual morph: Conidiomata dark brown, eustromatic, pycnidial, usually solitary, initially immersed, ultimately becoming erumpent, globose to cupulate, ostiole absent, dehiscence by rupture of the upper wall. Conidiomatal wall composed of thin-walled, pale brown cells of textura angularis in the basal part becoming thick-walled, darker cells of textura porrecta in the lateral wall. Conidiophores arising from innermost wall layer of the conidiomata, hyaline, cylindrical, septate, smooth-walled, usually branched at the base. Conidiogenous cells hyaline, holothallic, cylindrical, integrated, indeterminate, smooth-walled. Conidia hyaline, arthric, doliiform, truncated at both ends except for apical conidia which are subacute at the apices, unicellular, straight, smooth-walled, guttulate, formed by disarticulation of the conidiogenous cells from the conidiophore, produced in long, branched chains with the oldest conidia at the apex (adapted from Sutton 1980).
Type species: Phacidiella salicina P. Karst., Hedwigia 23(6): 85 (1884)
Notes: Sutton (1980) revised the generic concept of Phacidiella and accepted three species, P. asperulina (Bubák) B. Sutton P. salicina and P. tomispora (Berl. & Bres.) B. Sutton. Purohit and Chawla (1989) and Crous et al. (2007, 2014d) added three species, P. eucalypti Crous, P. podocarpi Crous & A.R. Wood and P. viticola Purohit & G.C. Chawla. However, Wijayawardene et al. (2017b) suggested that only P. salicina be accepted in the genus, but without giving any reasons. Here we accepted the six species mentioned above in Phacidiella (Sutton 1980; Purohit and Chawla 1989; Crous et al. 2007, 2014d).
The sexual morph of Phacidiella has been linked to Phacidiopycnis Potebnia, (= Potebniamyces) (Smerlis 1962; Johnston et al. 2014) and Pyrenopeziza (Sutton 1980), but these connections have not been proven by culture and molecular data. Crous et al. (2007, 2014d) showed that Phacidiella is related to Ostropales (Lecanoromycetes) based on ITS and LSU sequence data. However, the sequence data of type species P. salicina is not available, thus fresh collections are needed to confirm its placement.
Distribution: Austria, Finland, India, Kurdistan, Latvia, South Africa, Sweden (Sutton 1980; Purohit and Chawla 1989; Crous et al. 2007, 2014d).
Fig. 265 Phacidiella salicina (redrawn from Sutton 1980) a Vertical section of conidioma. b Conidia. c Conidiophores, conidiogenous cells and developing conidia.