Omphalotus olivascens  Bigelow, Miller & Thiers (1976)

The Jack O'Lantern mushroom, as it is commonly known is a staple on Oak stumps in the Bay Area. It tends to fruit profusely early in the season, up until January in some cases. Supposedly it fluoresces in he dark, but your mileage may vary. I think I imagined once seeing that effect, but I need to repeat the experiment with fresh material. Much sought after for dying.