Pleospora herbarum

Anamorph: conidiomata absent. Conidiophores developing from a small immersed stroma, 20–72 × 4–6 μm, erect, flexuous, often caespitose, 1- to 7-septate, pale to mid brown or olivaceous, with a swollen apical conidiogenous cell 7–11 μm diam., and slightly roughened toward the apex, with a single apical pore 5–8 μm diam. and a broad dark verrucose band below the apex; several successive conidiogenous cells may form by proliferation through the apical pore. Conidia 27-42 x 24-30 µm, broadly cylindrical to cylindric-ellipsoidal or ovoid to subdoliiform, olivaceous to brown, usually with three transverse septa and 1-3 longitudinal septa, often constricted at the central transverse septum, with a single basal pore ca 8 μm diam. and a minutely verrucose or echinulate outer wall, without a gelatinous sheath or epispore.
Teleomorph: ascostromata 300–500 μm diam., scattered, immersed to erumpent from the tissue of the host, globose or somewhat flattened, with a thick, rather irregular black wall, often containing only a few asci. Interascal tissue composed of thin-walled cellular pseudoparaphyses that are branched and anastomosed, and 2-3 µm diam. Asci 90–250 × 20–50 μm, cylindric-ellipsoidal to broadly saccate, short-stalked to almost sessile, thick-walled and fissitunicate, the apex rounded with a distinct ocular chamber, 8-spored. Ascospores irregularly biseriate, 26–50 × 10–20 μm, light to dark yellow-brown, ellipsoid to clavate, usually with 7 transverse septa, slightly constricted at the three primary transverse septa, finally muriform, smooth or verruculose, in some collections at least with a broad gelatinous sheath.