“This is where I saw the fairy ring,” said my mushroom guide, Angel Schatz. We paused in the deep shade of a nature trail improbably located a mile from a busy Central Texas highway. For a minute the two of us scanned the drifts of brown leaves, hoping for a flash of lavender that would signal the presence of a mushroom I had not heard of until a week before: the wood blewit. Like many fungi, it often grows in a natural ring that ancient European cultures attributed to fairies, pixies, or elves. The wood blewit is a comely and hardy fungus that grows worldwide, including in Texas. More importantly for my immediate purposes, it is a tasty fungus. We scuffed up a few leaves.…