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Mushroom Madness at Sycamore Grove Park 

Tree branches with white lichen or fungus growth, and patches of yellow-green lichen.

January 2025 - The annual Mushroom Madness event was enjoyed by 76 people on a beautiful sunny day. During the event, LARPD Rangers and volunteers teamed up with the Bay Area Mycological Society experts and led a foray for mushrooms along the Arroyo Del Valle from the Arroyo Entrance of Sycamore Grove Park. We crawled under trees, wandered through meadows, and rolled rotting logs to see how many different types of fungi we could find.  Among the plethora of fungi found, there were a few standouts: Turkey Tails, Earth Stars, Boletus species, Giraffe Spots, and the infamous Death Cap. 
 
The Turkey Tail (Polyporus versicolor) was found on decaying oak wood. Many cultures have used these mushrooms for centuries in herbal remedies, and they are now gaining a reputation for their amazing potential for supporting the immune system in the fight against cancer. 
 
We found an Earth Star (Astraeus Hygrometricus), which is a species of fungus that resembles a puffball when the outer layer splits and releases its spores. It has a beautiful star shape when mature.  
 
Boletus is a common mushroom family. It can be found in leaf litter throughout the forest floor. The King Bolete is one of the most sought-after mushrooms for eating. However, Boletacae are both edible and poisonous species, so only experienced mushroom experts should collect them. 
Peniophora, commonly called Giraffe Spots, is a genius of crust fungi, which are plant pathogens. This fungus was a new sighting in Sycamore Grove Park. 
 
The most ominous mushroom found was identified as the Death Cap. While this mushroom is the most common cause of fatal mushroom poisoning in California and the US, it is commonly found under Coast Live Oaks, forming a necessary and mutually beneficial bond with the trees. These mushrooms are only poisonous when eaten—any mushroom found in California is safe to touch. 
 
The presence of the Death Cap and other poisonous mushrooms are good reasons to always rely on expert mycologists when attempting to collect mushrooms. An excellent source of mushroom information is the Bay Area Mycological Society (bayareamushrooms.org). They host several events around the Bay Area every year! Be aware: no mushrooms may be collected from Sycamore Grove Park. 
 
In all, we identified 36 different mushroom species on our hunt and added two new species to Sycamore Grove Park's mushroom list this year (Peniophora and Tricholoma Saponaceum). This species count is significantly lower than the last few years due to these beautiful warm and dry days we have had over the past month. Over the ten years we have collected mushrooms for the January Mushroom Madness event, we have identified 196 distinct species. 
 
Join us next year for our annual Mushroom Madness event – maybe you will be the first to find a brand-new species in the park! 

This article was written by Polly Krauter, LARPD Open Space Volunteer.