Collection location: Howarth Park, Santa Rosa, Sonoma Co., California, USA [Click for map]
I didn’t observe this until it’s brilliant youth had already passed. It looked like F. septica but I was confused by the removable crusty shell and the dark spore mass, which I’d never encountered before. Fortunately for me, lots of folks have written about F. septica and published online, helping to clear up my confusion. The first photo documents how it looked when found.