Mushrooms on the prairie

The heavy late fall rains last week brought on an enormous flush of mushrooms on Toby’s Prairie, and to a lesser extent on the Pocket Prairie. Amanda and Susan discovered them while seed collecting. The species was Agaricus campestris,  common name “meadow mushroom”, which is closely related to the cultivated species (A. bisporus).

Among other things, the meadow mushroom is known for forming circles called “fairy rings”on lawns, golf courses, or meadows. Despite the literature, there is nothing mystical or mythical about a fairy ring. It is just a growth phenomenon. The mushroom mycelium grows out from a single center (probably starting from a single spore), growing on the rich organic matter of the lawn or prairie.  It may grow for quite a while in this vegetative state, but generally in response to a good rain (we had 1.5 inches last week) it undergoes morphogenesis and forms fruiting bodies at the periphery of the ring.

Part of a "line" of mushrooms, a fragment of a fairy ri

In a tallgrass prairie a fairy ring is not as photogenic as it is on a lawn. Also, sometimes a complete ring is not formed, only parts of a ring (arcs), and this is what we have in Toby’s Prairie.  The photo here shows an example.

Although we see occasional mushrooms in our prairies, this is the first time we have seen such an enormous flush. The mushroom is a saprophyte, which means it grows on dead plant material. Because of  the impact of the drought, there is a lot of mushroom food on the surface of the soil, and fruiting was brought about by the good fall rains.

This mushroom should have no detrimental effect on the prairie. The extensive mycelium that it forms on the surface of the soil will eventually die and become incorporated into the rich organic humus that a prairie makes.

Yes, this species is edible!