Anamorph: Leptostroma-like. Conidiomata supracuticular, 80-110 x 60-90 µm, frequently aggregating into larger compound structures, irregular in form but mostly elliptical to oblong in outline, strongly flattened, often confluent, dark brown to black. Upper wall composed of small dark brown very thick-walled angular to polygonal cells 4-6 µm in diam., opening with irregular longitudinal splits. Lower wall apparently absent. Conidiophores absent. Conidiogenous cells apparently developing from the inner surface of the upper wall. Conidia 5-6 x 1.3-1.8 µm, ± cylindrical, sometimes slightly isthmoid, the apex obtuse to rounded and the base acute to obtuse, aseptate, hyaline, thin-walled, smooth, without an epispore, gelatinous sheath or appendages. Teleomorph: ascomata thyriothecia, densely scattered, supracuticular, generally occurring in abundance and ± covering large parts of the petioles. Solitary ascomata usually circular to elliptical, ca 0.1 mm diam., but often several confluent into crusts up to 1 mm across. Upper wall radiate, splitting irregularly or often with a star-like or circular fissure. Hypostroma none or almost none. Interascal tissue apparently absent. Asci 25-30 x 10-12 µm, cylindrical to saccate. Ascospores (11-) 15-18 (-20) x 2.5-3.5 µm, generally allantoid, long 2-celled but finally (always?) 4-celled.
Description of the teleomorph adapted from Holm & Holm (1977).