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These are commonly found on lawns or green meadows. When they first appear, they are white with the shaggy covering, resembling an English barrister's wig. Its gills are initially white but soon turn to pink and then black within hours. Even if not picked they will begin digesting themselves soon after shedding their spores. This is because they rapidly absorb moisture from the atmosphere, a trait called deliquescence. (If you use that word in a sentence three times, you still probably won't remember it.)
|Multiple ages of Inky Caps- Wikimedia|
|Common Inky Cap- Wikimedia|
By looking carefully you are unlikely to confuse it with the shaggy mane. Its cap is smooth, tan to brown with lines or ridges radiating from the center. The important thing is to remember which is which. For those of us with inability to remember such details it is best to follow the rule, "Don't drinky with an inky."
Mushroomexpert.com has much more on other inky cap mushrooms.