Ascocarps in vertical section intraepidermal to partly subepidermal. Upper wall mostly 15-20 µm wide, comprising brown to pale brown, slightly thick-walled cells, with a 60 µm wide layer of thin-walled, hyaline, vertically oriented cells adjacent to the ascocarp opening. Exposed face of broken upper wall becoming lined with cylindric, thin-walled, hyaline to pale brown cells. Lower ascocarp wall 15-20 µm wide, of 3-4 layers of thick-walled, dark brown cells.

Paraphyses 2-2.5 µm diam., slightly swollen at apex, developing short side branches, extending 40-50 µm beyond asci. Asci 220-245 x 6.5-8 µm, cylindric, tapering to more or less acute apex, wall not thickened, 8-spored. Ascospores 125-180 x l-1.5 µm, 0-1 septate, with gelatinous sheath.

Pycnidia in vertical section subglobose, intraepidermal. Upper wall 10 µm wide, comprising dark brown, thick-walled cells, obsolete near centre of pycnidium where 1-2 host epidermal cells remain intact. Lower wall 5-10 µm wide, lined with conidiogenous cells, solitary, 7.5-12 x 1.5-2 µm, cylindric, thickened collarette at apical conidiogenous locus. Conidia 2.5-3.5 x 0.8 µm, cylindric, 0 septate, hyaline.

ETYMOLOGY: irregulare = irregular; refers to variable, often irregular shape of ascocarps.

NOTES: L. irregulare can be distinguished macroscopically from the other Lophodermium spp. occurring on Epacridaceae by its large, dark pycnidia which have a distinct, paler area near the centre. It is the only Lophodermium species on Epacridaceae with asci over 200 µm long.

See also notes under L. mangatepopense.