A Western Jumbo Gym (Gymnopilus ventricosus) mushroom was found in Golden Gate Park recently.
San Francisco Recreation and Park Department Natural Resource Manager Lisa Wayne said the mushroom was found near Metsen Lake in Golden Gate Park on pine stumps in a reforestation plot. According to Wayne, they are common in wooded areas on pine stumps and wood chips. The Western Jumbo Gym is one of the largest mushrooms – it can grow to be a foot in diameter.
For more information, follow this link: https://en.wikipedia.org/wiki/Gymnopilus_junonius