Phyllosticta concentrica Sacc., Nuovo Giorn. Bot. Ital. 8: 203. 1876.
Index Fungorum: IF168526; Facesoffungi: FoFxxxxx; MycoBank: MB422530.
Pathogenic on withering leaves of Hedera helix. Sexual morph: Unknown. Asexual morph: Conidiomata up to 400 μm diam., pycnidial (on PNA), solitary, black, erumpent, globose, exuding colourless conidial masses, pycnidia elongated in culture on PNA. Peridium up to 30 μm thick, composed of several layers of textura angularis, inner wall of hyaline textura angularis. Ostiole up to 25 μm diam., central. Conidiophores 12–20 × 4–6 μm, subcylindrical to ampulliform, reduced to conidiogenous cells, or with 1 supporting cell, that gives rise to 1–2 conidiogenous cells. Conidiogenous cells 7–10 × 3–6 μm, terminal, subcylindrical, hyaline, smooth, coated in a mucoid layer, proliferating several times percurrently near apex. Conidia (10–)11–13(–14) × (6–)8(–9) μm, solitary, hyaline, aseptate, thin and smooth-walled, granular, or with a single large central guttule, ellipsoid, tapering towards a narrow truncate base, 2–3 μm diam., enclosed in a thin persistent mucoid sheath, 1–2 μm thick, and bearing a hyaline, apical mucoid appendage, (5–)8–12(–15) × (1–)1.5 μm, flexible, unbranched, tapering towards an acutely rounded tip.
Culture characteristics: Colonies flat, spreading with sparse aerial mycelium, and feathery, lobate margins, reaching 30 mm after 2 wk at 25 ºC. On PDA surface greenish black, reverse iron-grey; on OA surface iron-grey; on MEA surface olivaceous-grey in centre, pale olivaceous-grey in outer region, olivaceous-grey underneath.
Representative isolates: Italy, Padua, on withering leaves of Hedera helix, Jul. 1875, syntype (L); Sardegna, Cologne near Oleina, leaf litter of Hedera helix, 31 Aug. 1970, W. Gams, epitype CBS H-16992, CBS 937.70 = MBT176244 (ex-epitype culture). Spain, on living leaf of Hedera sp., 10 Jul. 2010, U. Damm, culture CPC 18842 = CBS 134749.
Host: Hedera helix (Wikee et al. 2013).
Known distribution: Italy, Spain (Wikee et al. 2013).
GenBank Numbers: ITS - FJ538350, LSU - KF206291, TEF - FJ538408, ACT - KF289257, GPDH - JF411745.
Notes: Phyllosticta concentrica, and its purported sexual state, Guignardia philoprina, represent different taxa, with each name representing a species complex for which numerous old names are available. Phyllosticta concentrica was originally introduced by Saccardo for a species occurring on Hedera helix in Italy, but which appears to be common in Europe on this host.
Wikee S, Lombard L, Nakashima C, Motohashi K, Chukeatirote E, Cheewangkoon R, McKenzie EHC, Hyde KD, Crous PW (2013) A phylogenetic re-evaluation of Phyllosticta (Botryosphaeriales). Studies in Mycology 76: 1–29.