Gemmed Amanita, Amanita gemmata

Before anyone eats any white-gilled and white-spored mushroom, they need to be able to identify species in the genus Amanita. The name Amanita comes from an ancient term for a mushroom, and contains a few edible, but most notably some of our most poisonous mushroom species.

Amanita gemmata, Gemmed Amanita may actually be part of a species complex, or a species that maybe hybridize also with other Amanita species. For that reason, there are varying opinions about the extent of this particular Amanita’s toxicity, but there is universal agreement it should never be eaten.

The “gems” on the Gemmed Amanita, are small pieces of white tissue that adorn its yellow cap, that are the remnants of a universal veil that completely enshrouds the immature mushroom when it first emerges as a “button” above its underground fungal mycelia.

As the stalk (or stipe) of the mushroom elongates, and as the cap opens or expands, this veil is torn into patches or into small white pieces that are termed “warts.” Additionally, along the ground the universal veil is similarly torn, but is generally retained at the very bottom of the stipe as a small, delicate, rounded bowl or cup (termed a “volva”).

As with most Amanitas, the Gemmed Amanita’s white gills don’t connect directly near the top of the stipe. Also, if it hasn’t fallen off, a partial veil is usually retained as a white ring (or annulus) around the middle of the stipe.  (In the photo it is torn, and hanging down like a white strip.) Some species lack an annulus, and the volva can be easily left behind when one picks the mushroom. Finally, rain may wash off the identifying warts or gems (particularly around the margin) of the mushroom’s cap.

Amanitas are “mycorrhizal” meaning they grow in association with the roots of various surrounding tree species, and thus greatly benefit the tree’s ability to capture and take up nutrients.