Anamorph: not known.
Teleomorph: stromata absent. Ascomata apothecia, 2-3 (-4) mm diam., erumpent through the bark in clusters, initially closed, opening into uneven discoid structures, lacking a stipe, the outer surface leathery and sometimes inconspicuously striate, dark brown when hydrated and yellow-brown when dry with a ragged pale cream or white edge. Interascal tissue of filiform paraphyses, the apices clavate to ca 4 µm diam., with a light brown encrustation. Asci 75-80 x 8-9 μm, cylindric-clavate, fairly thick-walled but not fissitunicate, with a rounded to almost truncate apex, 8-spored. Ascospores biseriate above, generally obliquely uniseriate below, 12-15 x 3-3.5 μm, allantoid or rarely ellipsoidal, hyaline, aseptate, with a globular refractive body at each pole, without a gelatinous sheath or appendages.
Not formally assessed, but currently known only from two confirmed records. The species may well be under-recorded, but could well be rare as it is a reasonably conspicuous species.
Encoelia glaberrima also occurs on Carpinus, but has much smaller ascospores (6-8 x ca 1.5 µm in size) and larger ascomata (to ca 25 mm diam.)
On dead attached or fallen branches of Carpinus betulus and Populus species.
Widespread. Reported on Carpinus from VC17 Surrey and VC20 Hertfordshire; these could refer to a different taxon. Records from Kent need confirmation, and may be referable to Encoelia glaberrima.