Asteromella ovata Thüm., Mycoth. Univ., cent.17: no. 1689 (1880) Fig. 1
Index Fungorum number: IF 197904; Facesoffungi number: FoF 06214
Epifoliar or epiphytes on the upper surface of living leaves leaves of Menispermum canadense L. (Menispermaceae). Colonies forming blackened 0.2–0.4 mm circular areas. Sexual morph: Undetermined. Asexual morph: Pycnidia 250–430 µm high × 196–210 µm diam., (x̅ = 343 × 203 µm, n = 10), hypophyllous, dark brown to black, globose to subglobose, superficial with irregular margins, sometimes sparsely scattered or not entirely distributed on surface of leaves. Peridium 13–18 µm, thick walled comprised of cells of textura globulosa. Conidiophores reduced to conidiogenous cells. Conidiogenous cells enteroblastic, phialidic, integrated or less often discrete, determinate, hyaline (Sutton 1980, van der Aa & Vanev 2002). Conidia 6.7–8 µm × 3–5 µm (x̅ = 8 × 5 µm, n = 10) cylindrical to ovoid, hyaline, 1-septate, ellipsoid to cylindrical apparently with 2-guttules, eguttulate.
Material examined – PARMA, Parma Botanical Garden, on leaves of Menispermum canadense L. (Menispermaceae), November 1878, Passerini (S-F40912, holotype).
Economic significance – The anamorphic genus Asteromella is a pathogenic genus causing dark lesions, stains, leaf spots and discoloration of host plant leaves in Poland (Ruszkiewicz-Michalska 2016). Asteromella is also associated with leaf blotch symptom of lime trees (Butin & Kehr 1995). The genus was also reported on withering leaves of Prunus armeniaca 'Aprikose von Nancy' (Bedlan 2014) as well as ring spots on Brussels sprout and cabbage in UK (Koike et al. 2007). The genus Asteromella is also a pistachio pathogen (Vitale et al. 2018).