Niesslia aemula  

Anamorph: Acremonium-like. Conidiophores absent or reduced to short subtending cells. Conidiogenous cells elongate, slightly tapering throughout their length, proliferating percurrently. Conidia 4.5–7.5 × 1.2–2.0 μm, mostly cylindrical, hyaline, aseptate, smooth- and rather thick-walled. Chlamydospores absent.
Teleomorph: stromata absent. Ascomata perithecia, 125-185 μm diam., scattered, superficial, ± globose, dark brown to black, collapsing when dry, spiny in the upper part, composed of an outer layer of ± globose to epidermoid cells with irregular hyphae extending over the surface, and an inner layer of hyaline flattened cells. Spines sparse to numerous, mid to dark brown, 30-65 μm long, 5-6 μm diam. at the base and cylindrical or tapering slightly towards the acute to obtuse apex, very thick-walled. Interascal tissue not seen, the ostiole lined with periphyses. Asci 46–58 × 7–9.5 μm, cylindric-clavate, short-stalked, thin-walled and not fissitunicate, the apex obtuse to truncate, with a minute apical ring, 4-spored. Ascospores arranged obliquely uniseriately to biseriately, 11.2–13.8 × 3.5–4.2 μm, ellipsoidal, hardly constricted at the ± median septum, 4-guttulate, smooth to very finely warted, without a gelatinous sheath or appendages.

Description adapted in part from Gams et al. (2019).