Psathyrella delineata is not delineated in Mushrooms Demystified . Arora says to leave the genus to "professional psathyrellologists" since "few fleshy fungi have less to offer the average mushroom hunter" (p. 361). The National Audubon Society Field Guide to North American Mushrooms only references it as a lookalike to Psathyrella rugocephala , which has a tawnier cap and larger spores. Fortunately, this species (I think) is described in Mushrooms of the Midwest. The description there fits my specimen pretty well. But given the paucity of information I found on the mushroom, I could be wrong. Amateur mycologists ever depend on someone else's taxonomy, and we don't know what we don't know. A monograph on the Psathyrella genus by Alexander Smith describes four hundred North American species of Psathyrellas. I wonder which of those four hundred descriptions best fits what I found. So, what did I find? The mushroom was growing on a fallen log in cluster
Here you will find a record of my forays into the woods looking for mushrooms. If you're interested in what kinds of mushrooms grow in south central Illinois and when they grow, then please join me.