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Our specimens were found growing in hemlock pine duff; in hardwood and coniferous forests; range widespread but most common in Northeastern USA and Southeastern Canada; June to September; scattered. Cap begins as hemispheric and becomes more convex and eventually flat as mushroom ages; cap color ranging from bright yellow to bright orange with white, yellow, or orange warts; gills free, white to cream-colored, close to crowded; stipe pale to bright yellow with white to pale yellow volva at base; white to bright yellow universal veil. The distribution of this species is widespread and potentially global. Sanmee et. al. reports that a specimen of A. frostiana was found in Thailand in 1962, but argues that that specimen was in fact the morphologically similar A. rubrovolvata (Sanmee 2008). Further research is required to determine the phylogenetic relationship between the two species and their respective distributions. We are fairly certain that our specimens are A. frostiana, but it is possible that some or all of our specimens are in fact the morphologically similar A. flavoconia. A. frostiana possesses a whiter stipe and a lined cap margin as well as a more persistent volva. Spores of A. frostiana produce a negative amyloid reaction when exposed to Melzer's reagent, an iodine solution used in fungi identification (Leonard 2006). Melzer’s reagent can be used to distinguish the two species, as A. flavoconia has amyloid spores, but this test requires microscopy to complete, which was not something we had access to during this study. ID number: 02.01.02.2021
White, Kathleen R.; Jergensen, Jacqueline A.; and Lam, Ada, "Amanita frostiana" (2021). Mycological Herbarium of Macrofungi from the East Brook Valley. 4.