Anamorph: Fusarium graminearum agg. Microconidia absent. Macroconidia produced from doliiform phialides 10–14 × 3·5–4·5 μm, formed laterally or on short multibranched conidiophores; sporodochia may form in older cultures. Conidia often formed sparsely, 25–50 × 3–4 μm, falcate, sickle-shaped or markedly dorsi-ventral, 3- to 7-septate, with a well developed, often pedicellate foot cell. Teleomorph: ascomata perithecia, forming in superficial clusters on a thin basal stroma, 140–250 μm diam., ovoid, with a rough tuberculate outer wall, showing varying degrees of lateral collapse when dry, dark blue-purple, reddening in lactic acid. Peridium with an outer stromatic layer 17–31 μm thick, of globose cells 5–12 × 1·5–3·5 μm and a thin inner layer of compressed thin walled cells. Interascal tissue absent, but apical paraphyses are present, to 25 x 3-4 µm, very thin-walled, the apices obtuse. Asci 60–85 × 8–11 μm, clavate, with a short stipe, the apex obtuse, very thin-walled, not fissitunicate, without a clear apical stucture, not blueing in iodine, (4–6) 8-spored. Ascospores obliquely uniseriate or biseriate, 19–24 × 3–4 μm, narrowly fusiform, curved, with obtuse ends, initially 0–1-septate, finally 3-septate, hyaline to pale yellow, smooth, thin-walled, without an epispore, gelatinous sheath or appendages.