Don't know what it is, but be sure the dogs can't get to it, Carol

No dogs here. :)

You might try the Moss, Ferns, and Cryptogams forum.

It would be helpful to be able to see the underside, whether the edge curves under, and also to see if it has gills (and the pattern - how they are arranged) or a spongey underside, and the color of te underside and stem.

It's important to determine if it contains fluid. Some mushrooms ooze a sticky liquid (called latex) when they're cut or damaged. Whether it has a liquid and the color of it is often important to an ID.

Of course, this means you would have to lift it out and cut it. Personally, I would wear gloves to do this but then, I'm deathly allergic to mushrooms and just washing the dishes when they've been served is enough contact for me to develop hives. Whether you wear gloves or not, be sure to wash your hands carefully - unsure if this is poisonous, and if it is, you wouldn't want to touch anywhere near your mouth after handing it.

Photo the stem and underside, then cut in half and photo again. Note carefully any fluid that oozes from the gills or "meat". You might want to check the mushroom group to see if there are other observations you should make as well.

Hi Kathy,

Finally pulled today when I spotted another and a few different kinds in the lawn. What on earth is this sudden mushroom invasion lol?

Here are photos as you suggested:

And sliced. No liquid as far as I can tell.

Have you had any trees removed in recent years? After my big oaks were cut down, I had scads of the ugliest mushrooms I've ever seen.

That could explain why you suddenly got them. Mushrooms/toadstools develop in rotting wood.

Sugi, in the yard, unless they are associated with a tree with which they have a symbiotic relationship, mushrooms tend to show up where there is an adequate supply of food. This can be dung (including doggie doo doo), rotted stumps, or lots of compost, and in particular, when it has been very damp or rainy for several days.

The food source might not be obvious: they usually indicate that decay is happening underground. That's a good thing, as the decay of organic matter (leaves, twigs, tree stumps) puts nutrients back into the soil. Where we have bark mulch and then had leaf and twig mulch decaying into compost in a shady area of the garden is where we saw them develop a few years ago. Aside from that, we rarely see mushrooms in our yard and if we do, it's usually only in our compost area after a particularly damp, rainy spate of weather. Our compost area is outside of the main garden area. Then again, we don't have any grass and very little mulch; we turned the entire yard (1/2 acre) into a garden and we mulch our garden beds with compost, not mulch. We only use mulch over a wide path (a driveway, actually), that extends along the side of our property from front to the back garden and that is pretty much the only place where we see them in the yard.

I originally thought this might be a mushroom of the Lactarius family and it physically resembles them, but the fact that it did't ooze any liquid puts that ID in question.

I notice that this is growing in mulch. In our yard, the main place where we saw mushrooms was in the one area (a driveway) that we mulched. We had put down a very thick layer of mulch and then Mother Nature did the rest. Mushrooms in grass show up when you have a lot of thatch decaying. In both locations, however, conditions have to be perfect, a mix of the correct temperature, moisture (we saw them develop during a particularly wet spring) in an area where they would have ample food.

it's likely the spores have been in the mulch and your soil all along - they are ubiquitous - and the climate allowed them to develop. The structure above the soil is only a small part of the structure; there is likely an extensive underground network which is why they are springing up elsewhere. My own experience in our most recent garden is that we rarely see them sprout, they only sprout when the weather conditions are "perfect" for them, and they have been known to skip years that were particularly dry or where we didn't water as extensively. Over the years, however, in the other places I've lived - always in New England until now - that has been similarly my experience... mulch or leaf litter or compost, heavily thatched lawn, a tree stump, rain, the right temperature... we saw them occasionally, but they were rarely a serious problem aside from the fact that not knowing much about them, we removed the visible structures to protect our pets.

We always picked the mushrooms as we didn't want our curious dogs to eat any. You can read about our experience - limited as it was - on our blog. It includes some information about the underground network that develops. The link I've included is to a post I wrote about faerie rings and in particular, one that developed in bark mulch in our yard in 2011. (This is a personal blog abut our garden; we don't have a garden-related business.) I believe we had a few mushrooms surface in that same area in 2012, none in 2013 or this year.

In that area, the mulch was fairly old and decaying but we thought we would let it be for one more year. We had put a very thick layer (4-5 inches) on a base of clay. We had piled some twigs and leaves and left during spring clean-up and left them when the weather turned rainy. The following year (2012) we added a very thin layer of bark mulch, and this spring (2014) we added a substantial covering of bark mulch as the existing mulch had decomposed dramatically.

My guess is that if you disrupt the mulch and perhaps de-thatch your lawn, you may possibly disrupt the cycle enough to eliminate much of the problem. On the other hand, even if you do nothing, since weather plays a pivotal role, you may or may not see any of them sprout next year.

Here is a link that might be useful: Faerie Rings