Fusarium graminearum
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 (Gibberella zeae): 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.
Not formally assessed, but this is a reasonably common species with a broad host range (as currently circumscribed). It is unlikely to be threatened in natural habitats.
As accepted here, Fusarium graminearum is likely to be a species complex. Cultural and molecular studies are needed in order to resolve the taxonomy of UK species from non-crop environments.
The teleomorph has been reported from dead culms and leaves of a wide range of graminoid plants, including Carex, Glyceria, Phalaris, Phragmites and Typha.
Scattered throughout England and Scotland from Cornwall to Mull and Tiree, also from the Channel Is and ROI. This is certainly an under-representation of its distribution.