I think this is chlorophyllum molybdites I just want to confirm it. It was in my backyard Phoenix, Arizona. I had to dig it up before my dog ate more of it. Thanks Kelly
I know this was posted a number of months ago.... but this would be easier confirmed if there were a few more details; Spore print colour? Gill colour & arrangement, or notable colour after bruising &/or location of bruising with discolouration, odors noted, habitat (under conifers, in lawn, etc.) My first thought was Coprinus comatus, and my second was a different species of Chlorophyllum, one that isn't poisonous; C. brunneum . Check it out?
It could have been they seem to look like those but the dog got really sick she had blood in her stool and broke out in bumps all over. When I saw the blood I was really worried her liver was being damaged, but the vet said everything looked okay from the test's she ran on her kidney's and liver. Our dog recovered we look for them daily to make sure they don't eat any of them. It was growing on gravel that is around our lawn later I saw more growing on the lawn.
Could be a Podaxis pistillaris - known to cause histamine-like reactions you describe in a minority of people. Glad the dog was fine.