Lesions 400-1500 µm diam, the included leaf tissue hypertrophied, the outer part often distinctly browned and the central region flat and sometimes pale grey due to flaking away of the epidermis.
Anamorph not observed.
Stromata on both leaf surfaces, 120-300 (-750) µm diam, sometimes coalescing into irregular shapes, shining black, usually one per lesion, usually 1-loculate. In section: the leaf tissue surrounding stromata is filled with irregular crystalline ? starch deposits. Ascomata hologenous, the ostioles usually epigenous, 200-300 µm diam, ± globose, fairly strongly domed, the ostiole inconspicuous. Upper wall composed of a clypeus-like structure surrounding the ostiole, composed of epidermal cells filled with dark brown thick-walled irregular fungal cells, often completely occluded by melanin deposits, above a distinct ascomatal wall composed of hyaline thin-walled flattened cells. Outer and lower walls composed of an outer layer of strongly tanned compressed host tissue, and an inner layer 4-6 µm thick of hyaline thin-walled flattened cells. Periphyses very well-developed, to ca 40 µm long and 2 µm diam, cylindrical, thin-walled. Paraphyses copious, to 2.5 µm diam, very thin-walled, hardly tapering, septate, branching not observed. Asci developing from a crozier system, 116-154 x 11-13 µm, ± cylindrical, with a long tapering stalk (to ca 50 µm), thin-walled at all stages, the apex rounded to truncate, with a conspicuous apical ring 3-4 µm diam and ca 1 µm thick, 8-spored. Ascospores arranged obliquely uniseriately, 13.5-15 x 6-7 µm, cylindrical, often weakly isthmoid, the apices rounded to acute, thin- and smooth-walled, hyaline, aseptate, with one or two large guttules, lacking a gelatinous sheath.
Not formally assessed but potentially Endangered. The species is only known from one locality, which lacks statutory protection.
This species differs from Fremitomyces punctatus by the ascomata in much less well-developed stromata, and very slightly larger ascospores which tend to be isthmoid. An anamorph is not known. It is superficially similar externally to Phyllachora tanensis, but that has a typical Phyllachora ascomatal structure with distinctly melanized walls.
Recorded from living leaves of Erythroxylum seychellarum.
Only known from the island of Mahé (Seychelles).