Cercostigmina U. Braun, Cryptog. bot. 4(1): 107 (1993).
Index Fungorum number: IF 25183; Facesoffungi number: FoF 08593, 3 morphological species (Species Fungorum 2021), molecular data unavailable.
Leaf spots amphigenous, also at stems, elliptical, later often confluent, brownish to greyish brown, surrounded by a darker brown margin 1–2 mm wide, patches sometimes somewhat sunken with rather raised margin, spots less conspicuous on brown necrotic leaves. Caespituli amphigenous, punctiform to pustulate, scattered to dense, often in concentric zones, dark brown to blackish, often accompanied by spermogonia and mycosphaerella-like ascomata. Mycelium internal; hyphae branched, septate, sub hyaline to olivaceous, occasionally darker, above all around stromata. Asexual morph: Stromata deeply immersed, later erumpent, well-developed, large, consisting of a basal prosenchymatous stratum, of interwoven hyphae surrounded by a palisade-like mass of dense, parallel, closely septate, branched hyphae, cells pale olivaceous, thin-walled, smooth, giving rise to conidiophores at their distal ends. Conidiophores numerous, arising from stromata, loose to usually dense, forming sporodochial conidiomata, erect, straight to somewhat sinuous, but not geniculate, unbranched or only rarely branched, aseptate or only with few septa, pale olivaceous to very pale olivaceous-brown, thin-walled, smooth; conidiogenous cells integrated, terminal or conidiophores reduced to conidiogenous cells, with a single terminal locus, truncate to slightly convex, monoblastic, determinate to percurrent, with fine annellations. Conidia solitary, cylindrical, sub cylindrical to obclavate-cylindrical, straight to curved, (0−)1–7-septate (in vitro conidia to 180 µm long and to 10−septate), pale olivaceous, thin-walled, smooth, apex obtuse to subacute, base sub truncate to short obconically truncate, hila unthickened, not darkened. Sexual morph: Unknown (Adapted from Braun et al. 2014).
Type species: Cercostigmina concentrica (Cooke & Ellis) U. Braun
Notes: Cercostigmina was introduced by Braun (1993) with C. concentrica as type species. Cercostigmina is characterized by deeply immersed stromata with a basal prosenchymatous stratum, loose to usually dense conidiophores, solitary sub cylindrical to obclavate-cylindrical conidia. The placement of C. concentrica, previously known as P. concentrica was suggested in Pseudocercospora (Morelet 1993). Whether Cercostigmina is a distinct genus in Mycosphaerellaceae or a synonym of Pseudocercospora is still unclear and needs to be confirmed by DNA sequence data. In this study, Cercostigmina is treated as a doubtful genus in Mycosphaerellaceae.