Collection location: Howarth Park, Santa Rosa, Sonoma Co., California, USA [Click for map]
Found in a lawn in my neighborhood. Pileus was mostly dark brown when found but as I walked home the umbo turned tan and spread nearly to the margin. Spore print looks black to the naked eye but a very dark brown with a lens. Stipe was a silvery white when first encountered, turning brown where I held it. There appeared to be a powdery covering of some sort that rubbed off. Very fragile.