Phyllachora dactylidis  

Conidiomata not seen; present but rare fide Parbery 1967, with filiform conidia 16-18 x ca 0.5 µm, produced from elongate conidiogenous cells 15-22 x 2.5-3 µm in size, narrowed at the base and tapering towards the apex.
Ascomata 300-400 (-500) x  180-250 µm, 160-200 µm thick, occasionally confluent with two perithecia as loculaes within a common stroma, oblate to globose, usually slightly elongate parallel to the venation of the host, amphigenous, the ostiole epigenous, rather inconspicuous. Peridium irregular in thickness and distorted by host tissues, composed of several layers of dark brown flattened cells. Interascal tissue copious, composed of thin-walled paraphyses 1.5-2 µm diam., often branching near the base and lining the base and mid walls of the ascoma, merging into elongate periphyses around the ostiole. Asci 100-120 x 17-20 µm, often somewhat broader immediately before discharge due to the ascospores increasing in size, cylindrical to cylindric-saccate, short-stalked, thin-walled and not fissitunicate, the apex obtuse to rounded, apical structures not seen, 8-spored. Ascospores uniseriately arranged, 15.5-18.5 x 9-10 µm (measured in water), cylindric-ellipsoidal to cylindric-ovoid, occasionally beaked at one end, aseptate, hyaline, thin- and smooth-walled, without a gelatinous sheath.