Didymium trachysporum G. Lister (1923: 113)

Lectotype (designated by Lado & Wrigley de Basanta 2018):— UNITED KINGDOM. England: Essex, Leytonstone, 51.569 N 0.010 E, 24 Jul 1917, B.M. 2251 A [BM001089814] (BM!). — Studied syntype: UNITED KINGDOM. England: Essex, Leytonstone, 51.569 N 0.010 E, 25 Jul 1917, B.M. 3228 [BM001095143] (BM!) .

The lectotype material is very scarce and we have not sampled it for further invasive studies. Our description is based on microscopic characters of the syntype material only.

This species is characterised by its fructifications forming globose sporocarps or short whitish plasmodiocarps, double peridium with a smooth or wrinkled outer crust of closely compacted calcareous granules, which fructify on remains of straw, manure and dead leaves (Lister 1925). The very marked sporal ornamentation separates this taxon from other species of the genus.