Fusarium flagelliforme represents phylo-species FIESC 12 (O’Donnell et al. 2009), a fully supported clade (ML & MP-BS = 100 %; PP = 1.0), closely related to F. longifundum in the Equiseti clade. Similar to F. longifundum, this species lacks conidiophores and conidia on its aerial mycelia, but does produce abundant sporodochia and sporodochial conidia on the carnation leaf pieces and surrounding medium. The sporodochial conidia of F. flagelliforme ((3–)4–5(–6)-septate; 37–85 × 3–5 μm overall) are larger than those of F. longifundum ((3–)5(–6)-septate; 21–76 × 3–5 μm overall). This species appears to be restricted to Europe, mostly associated with cereals.