Critical revision of type material of Stemonitales (Myxogastria) at the Natural History Museum London (BM) Author Moreno, G. gabriel.moreno@uah.es Author Castillo, A. gabriel.moreno@uah.es Author Thüs, H. Current Address: State Museum of Natural History Stuttgart, Germany. & The Natural History Museum, London, United Kingdom text Phytotaxa 2018 2018-03-14 344 2 149 159 http://dx.doi.org/10.11646/phytotaxa.344.2.3 journal article 10.11646/phytotaxa.344.2.3 1179-3163 Stemonitopsis microspora (Lister) Nann. -Bremek. Sporocarp stipitate, up to 2.3 mm high. Sporotheca reddish-brown, cylindrical to fusiform, 2 mm high– 0.6 mm wide. Peridium evanescent. Stalk dark, cylindrical widened at the base, with a length of 0.3 mm . Columella tapering and reaching almost the apex of the sporotheca. Capillitium reddish-brown, dense, originating along the columela, with perpendicular main branches to columela and a surface network with small meshes and scanty free ends. Spores globose, 3.3–4.8 (–5) × 3.3–4.7(–5) μm, av. 4 × 4 μm, Q av =1 (n = 25), violaceous very pale to hyaline and faintly reticulated by LM. Under the SEM, the spore ornamentation is formed by a reticulum with no prominent walls (figs. 8a–g).