Diaporthe pholeodes
Anamorph: stromata 0.8-1.2 (-1.5) x 0.6-1 mm, similar in form to the teleomorph stroma. Conidiomata single, irregular in form, with a short central blackened ostiole and hardly pigmented walls. Conidiophores absent, or only as short subtending cells. Conidiogenous cells 7-11 x 2.5-3 µm, cylindrical but often tapering towards the apex, proliferating percurrently. Alpha conidia 7.5-9 x 2.5-3 (-3.2) µm, fusiform to cylindric-fusiform, the apices acute to obtuse, aseptate, hyaline, usually with two large guttules, thin- and smooth-walled, without an epispore, gelatinous sheath or appendages.
Teleomorph: stroma surface heavily blackened or encrusted, entostromatic areas often limited in size (1-3 x 0.5-1 mm) or more widely effuse. Margin sharply defined, but not with a differentiated line. Ventral zone definite. Ascomata perithecia, scattered singly. Ostioles short-cylindric. Ascospores 12-14 x 2.5-3.5 µm.
Not assessed; more work is needed on species delimitation and relationships.
The teleomorph was described as intermediate in form between the D. arctii and D. pardalota aggregates by Wehmeyer (1933). Phomopsis cirsii has larger alpha conidia and the beta conidia predominate.
On dead stems of Cirsium sp.
Recorded from a single location in VC3 S Devon, but probably more widespread.