American Caesar's Mushroom, Eastern Caesar's Amanita
Amanita jacksonii, the American Caesar's mushroom, is an eastern North American relative of the European A. caesarea. It has a sticky, brilliant red to orange cap that fades to yellow from the margin, a lined margin, yellow gills and stem, a yellow to orange skirt-like ring and a large white sack-like volva. René Pomerleau named it in 1984 from Québec; several nearly identical cryptic species occur in North America and Mexico.
Considered a choice edible, but it can be confused with toxic Amanita species, including the fly agaric (A. muscaria; white gills and stem, warty cap) and the deadly death cap (A. phalloides). Look for the combination of yellow gills and stem, a lined cap margin and a large white sack-like volva, and have the identification confirmed by an expert before eating.
Never eat a wild mushroom based on a web page — confirm with an expert.
Mycology is an evolving science: names, classifications and safety information change as research advances. Entries are compiled from cited sources and reviewed, but may be incomplete or out of date — check the sources, and never rely on this library alone to identify or eat a mushroom.
Habitat
Mycorrhizal with oaks and pines; alone, scattered or in groups. Season: Summer and fall.
Distribution
Eastern North America from Québec through the eastern United States, and Mexico to at least Hidalgo; observed in Belize. As a species group it is widespread east of the Great Plains; cryptic relatives occur in the lower Midwest, Texas, the Four Corners region and Mexico.
Characteristics
Cap: 5–12 cm; oval, becoming convex, often with a central bump; sticky when fresh; brilliant red or orange, fading to yellow from the margin inward; bald, usually without warts or patches; margin lined for 40–50% of the radius. Gills: Free or slightly attached, close, yellow to orange-yellow, not bruising. Stem: 8–15 cm long, 1–2 cm thick, slightly tapered upward; yellow, with orange to reddish fibres often in zones or chevrons. Ring: Yellow to orange, skirt-like. Volva: Large (4–8 cm high), white, sack-like. Flesh: Whitish to pale yellow, unchanging. Odor: Not distinctive. Spore print: White; spores about 7–13 × 6–8 µm, ellipsoid to broadly ellipsoid, inamyloid; basidia 4-spored, clamped. Chemical reactions: KOH on the cap turns the pigment yellow.
