In laboratory cultures Simocybe sumptuosa produces tiny slime drops with curved, binucleate conidia and ellipsoid, terminal or fusiform intercalary, binucleate chlamydospores. Chlamydospores occur also within the agar medium, but conidia do not. Noduli also form, and in one culture a few basidiomes developed. The mycelium is significantly denser beneath the noduli than between the noduli. Carpogenesis has been studied using stained microtome sections. Simocybe sumptuosa is exocarpic amphicleistoblemate.