Photo: Diane Edwardson, November 1, 2012. At first, I thought one of the heirloom tomato-stealing squirrels in our yard had moved onto dinner rolls. (Click on photo to enlarge.)
It's a Puffball Mushroom. Don't ask me which species - there are many. Check out the go-to source for California mushroom identification: Mykoweb.
Click here for all the fungus we've documented in the Red Car Property neighborhood.