I live in middle Tennessee above Nashville. These mushrooms have been growing in our backyard where I never put down any kind of fertilizers, weed killers, etc... Our development was built on land where cows used to me until the farmer sold some of the land for housing. Does anyone know what kind of mushrooms these are? Are they poisonous to my dogs? I already pulled them out of the ground but laid them down on the grass for you to see.