Key based on recordings of Jeppson et al. (2017). 1. Occurs among mosses on ± calcareous boulders, flat rocks, or stone walls in semi-shaded localities; Tulostoma niveum grows in dry sandy grasslands, on sand dunes, sand steppes and rupicolous steppe slopes. 2 2. Uninflated capillitial septa (partitions connecting the sterile fibers within a fruit body); Tulostoma melanocyclum yellow, stirrup-like/abrupt widenings of the capillitial septa. 3 3. Membranous exoperidium (outer surface of fruiting body) and spores (3)4.4 - 5.5(6) μm; Tulostoma brumale hyphal exoperidium and spores 5-7 μm. Tulostoma simulans Classification: Tulostoma brumale (All Fungi), Tulostoma melanocyclum (All Fungi), Tulostoma niveum (All Fungi), Tulostoma simulans (All Fungi)
