Mushroom Monday: Jackson’s Slender Amanita

Mushroom Monday: Jackson’s Slender Amanita

Today’s Mushroom Monday mushroom is Jackson’s Slender Amanita (Amanita jacksonii).  It’s also known as American slender Caesar and Eastern Caesar’s amanita.

What Does Jackson’s Slender Amanita Look Like?

When Jackson’s Slender Amanita mushrooms are young, they have caps with a red color and an oval shape.  As they age, the caps get flatter, change from oval to convex, and can form an umbo (bump in the middle).  Additionally, as they age, their color changes.  The red starts to fade from the edges and the edges become orange and yellow in color.  The mushrooms are hairless and don’t have patches nor warts.  The caps of mature mushrooms vary in size but can be around two to five inches across.

The gills of the mushroom are yellow/orange in color and spaced close together, and the stems are tall, thin, and yellow with orange fibers.  The total height of a mature mushroom can get to be around six inches or so.

Jackson’s Slender Amanita mushrooms resemble other mushrooms including Amanita caesarea (found in Europe), and toxic mushrooms such as Amanita muscaria and Amanita phalloides.

One noticeable trait of the mushroom is that it has a volva that has a sack shape.  The mushroom has a covering called a universal veil that it breaks through as it grows.  When it does this, it leaves it behind at the base, and this is what the volva is.

Where can Jackson’s Slender Amanita be Found?

Jackson’s Slender Amanita can be found growing from the soil in wooded areas in North America.  It could be alone or in groups.  The fruit of the mushroom appears toward the end of summer up to the start of fall.

Why Kind of Relationship Does Jackson’s Slender Amanita Have With Trees?

Jackson’s Slender Amanita has a symbiotic mycorrhizal relationship with trees, particularly oak trees.

If you like learning about mushrooms, check out our other Mushroom Monday posts and follow us on Facebook to keep up with new ones.