Stropharia rugosoannulata collected in Michigan State University gardens.
Ecology and relevance to society: Saprobic, often growing scattered (sometimes in clusters) on wood chips, in gardens and in other cultivated areas. S. rugosoannulata fruits in spring through fall and it is widely distributed. The wine capped form is edible and good, however, edibility for the white form is not reliable documented.
Cap: 4-15 cm; convex or broadly convex to flat; sticky when fresh, but often dry when collected, sometimes developing cracks in old age. Color is wine red to reddish brown, whitish throughout development.
Gills: Attached to the stem; whitish to pale gray at first, becoming purplish gray to purple black.
Stem: 7-15 cm long. 1-3 cm thick; dry; equal or with an enlarged base, bald or finely hairy; white discoloring yellowish to brownish in age. A characteristic feature is the presence of a thick ring that is finely grooved on its upper surface (and often blackened by spores) and radially split on its underside .
Spore print: Dak purple brown to blackish
Microscopic features: Spores 10-14 x 6-9 um; smooth and broadly ellipsoid. Chrysocystidia present.
Chemical reactions: KOH olive green on cap of red form and yellow on cap of white form.
Kuo, M., & Methven, A. S. (2014). Mushrooms of the Midwest. University of Illinois Press.