Anamorph: not known.
Teleomorph: ascomata perithecia, 480-550 µm diam., globose, very minutely papillate, black, scattered through the squamules of the host. Peridium of 2-3 layers of angular to globose or slightly elongate dark brown thick-walled cells to ca 8 x 5 µm in size. Ostiole and upper part of peridium lined with short tapering periphysis-like structures to ca 15 µm in length and 4 µm diam. at the base, composed of 2-4 cells, becoming shorter near the ostiole. Asci in a basal fascicle, 30-35 x 7.5-9 µm, clavate, the apex sometimes attenuated, short-stalked, thick-walled and fissitunicate, 8-spored. Ascospores arranged biseriately, (9.5-) 10-11.5 x 3-3.5 (-4) µm, fusiform to fusiform-clavate, with a ± median septum, becoming pale brown to olivaceous while inside the ascus, fairly thick-walled, smooth, with a narrow gelatinous sheath that degenerates quickly on discharge.
Not evaluated; possibly threatened but very likely to be overlooked.
One of a small group of Stigmidium species with periphysis-like structures lining the upper part of the ascoma (Roux & Triebel 1994, Kocourková & Knudsen 2012); these probably do not belong in Stigmidium but sequences are not available.
On the thallus of Placynthium cf garovaglii, not causing obvious damage to the host.
Known from a single collection from VC64 MW Yorkshire.