Amanita jacksonii

Amanita jacksonii, also known as Jackson's slender amanita, American Slender Caesar, and Eastern Caesar's Amanita, is a North American species of fungus in the family Amanitaceae. It is a reddish-orange colored mushroom species which can be identified by its yellow gills, large, white, sacklike volva.

Taxonomy
It was given its current name in 1984 by Canadian mycologist René Pomerleau.

Description
The cap of the mushroom is 8–12 cm wide; oval at first, becoming convex, typically with a central bump; sticky; brilliant red or orange, fading to yellow on the margin; typically without warts or patches; the margin lined for about 40–50% of the cap's radius. The red pigment fades from margin toward the center with age. Gills are moderately crowded to crowded, orange-yellow to yellow-orange to yellow. They are free from the stem or slightly attached to it; yellow to orange-yellow; crowded; not bruising. The short gills are subtruncate to truncate. Its stipe measures 90–140 × 9–16 mm, is yellow and decorated with orange fibrils and patches that are the remnants of a felted extension of the limbus internus of the otherwise white volva. The spores measure (7.0-) 7.8–9.8 (-12.1) × (5.2-) 5.8–7.5 (-8.7) μm and are broadly ellipsoid to ellipsoid (rarely subglobose or elongate) and inamyloid. Clamps are common at bases of basidia. The flesh looks whitish to pale yellow, and does not stain on exposure.

Similar species
A. jacksonii looks similar to A. caesarea (Caesar's mushroom), which is found in Europe and North Africa, as well as poisonous species of Amanita.

Distribution and habitat
Its range extends from the Province of Quebec, Canada, to at least the State of Hidalgo, Mexico.

Uses
The mushroom is considered a choice edible, although it can be misidentified with toxic species such as A. muscaria and A. phalloides.