Not a plant, a mushroom: Shaggy Mane, Coprinus comatus. Found in Golden gate park by a friend and delivered to me, reverently, in a paper bag. We identified it and I ate about 1/4 to prove it wasn't poisonous. We left the rest in the paper bag to eat 24hr later, provided I was still alive. Sadly, I found it had spontaneously and completely deliquesced within those 24hr. All that's left is an inky black drippy mess. Will sow the spores in my garden and will hopefully get more. (And will eat them quickly if they do grow.)

Note: photo is not of actual specimen, but another of the same species stolen from the internet.