Poisonous?

[Synergy]

I live about 45 minutes from Philadelphia, PA. I found two clusters of these mushrooms in my backyard roughly 50 feet apart. The large ones photographed were in the grass at the exact location that a weeping willow tree once stood. It fell over a couple years ago, roots and all. It is a flat grassy area now. The small cluster grew on semi-fresh garden mulch. They appeared after a rainy day. They seemed to wither rapidly in the sunlight, but grew in open areas with no shade.

It is important that I try to find out if these are poisonous because I have 3 dogs. I suppose the volva is not a good sign.

[Dave W]

Is the mushroom in the first photo the same one as in photos 2 and 3? The middle photo on top looks like a species of Conocybe, probably C. apala, formerly C. lactea or C. albipes. Also known as the White Dunce Cap, this one has the reputation for being toxic. Spore print reddish-brown.

The ones in the bottom photos look like a different species. Maybe Panaeolina foensecii? Maybe a species of Psathyrella? Maybe a species of Panaeolus? Is the areas where they grew fertilized? Telling these types apart can be challenging. Some of these types contain toxins.

[Synergy]

Is the mushroom in the first photo the same one as in photos 2 and 3? The middle photo on top looks like a species of Conocybe, probably C. apala, formerly C. lactea or C. albipes. Also known as the White Dunce Cap, this one has the reputation for being toxic. Spore print reddish-brown.

The ones in the bottom photos look like a different species. Maybe Panaeolina foensecii? Maybe a species of Psathyrella? Maybe a species of Panaeolus? Is the areas where they grew fertilized? Telling these types apart can be challenging. Some of these types contain toxins.

Mushrooms 1&3 are different mushrooms that were right next to each other (about 5 inches apart). I forget which of those was in the second photo.

The small mushroom cluster was growing in an area that was fertilized. The open, grassy area that the large mushrooms were growing was fertilized nearby, but that was way back in June. I assumed that they were the same type of mushroom only because I found a couple tiny mushrooms next to the large ones that looked identical to the small mushroom cluster in the garden about 50 feet away.

[Synergy]

Also, the light may have distorted the color slightly. They were a little more tan on the cap than is evident in the photos, and the stalk was more of a smooth, firm whitish-green such that the stalk almost blended in with thick blades of grass.

[Dave W]

If the next-to-last ones --the cluster-- are the ones described as having green-tinged stalks, then maybe Panaeolus olivaceus applies.

Knowing which mushrooms were observed during which times of year is often necessary for making ID suggestions.

IDing LMBs (little brown mushrooms) to species requires well-developed skills, often including studying microscopic details. Some LBMs are poisonous.

[Synergy]

Thanks for the help!