California Mushrooms: Berkeley's Foraging Adventure

California is home to a diverse range of mushrooms, and the state's renowned academic institutions, such as the University of California, Berkeley (UC Berkeley), have played a significant role in studying and classifying these fungi. The UC Berkeley campus itself hosts over 200 species of mushrooms, including both edible varieties like chanterelles and porcini, and deadly species such as the Funeral Bell and Death Cap. The latter, Amanita phalloides, is responsible for the majority of mushroom poisonings worldwide and can be found on the UC Berkeley campus, particularly along campus creeks. The Bay Area Mycological Society, based in the East Bay, is dedicated to the art and science of wild mushrooms, and sponsors mushroom walks and other educational activities. California's mushroom ecosystem is a fascinating blend of beauty and danger, attracting both enthusiasts and researchers alike.

The UC Berkeley campus is home to over 200 species of fungi, including poisonous varieties like the Funeral Bell and Death Cap

The UC Berkeley campus is home to a diverse array of fungi, with over 200 species identified. This includes both edible and poisonous varieties, and even some newly discovered species. Among the poisonous mushrooms found on campus, the Funeral Bell (Galerina marginata) and the Death Cap (Amanita phalloides) stand out as particularly dangerous.

The Funeral Bell is a small brown mushroom with a broad cap that can range in color from gray-brown to yellow-brown, making it easily mistaken for edible fungi. Its toxicity arises from Amatoxins, which affect the liver and kidney function in humans and animals, potentially leading to failure if not treated promptly. Similarly, the Death Cap, which fruits after the first rains of fall and has been spotted on campus during summer, resembles edible mushrooms in both its immature and mature states. This deadly fungus contains the same Amatoxins as the Funeral Bell, and consuming just 30 grams of it can be fatal to humans. There is currently no known antidote for these toxins.

The presence of these poisonous mushrooms on the UC Berkeley campus underscores the importance of caution when encountering wild mushrooms. While some may be edible, the difficulty in identifying mushroom types means that harvesting them from the campus grounds is not recommended. Instead, it is advised to purchase mushrooms from grocery stores rather than foraging them, as misidentification can have severe consequences.

The abundance of fungi on the UC Berkeley campus highlights the need for a comprehensive catalog of North American mushroom species. Researchers have emphasized the importance of maintaining green and open spaces on campus, as these environments foster the growth of diverse fungi. The campus serves as a “type locality” for several species, meaning it is the site where the representative specimens of these fungi were found. This contributes to the scientific value of the UC Berkeley campus in the study of mycology.

The Death Cap, responsible for most mushroom poisonings globally, has no known antidote and as little as 30g can be fatal

The Death Cap mushroom, or Amanita phalloides, is a highly poisonous species of fungi that can be found in the Berkeley area. It is one of the most poisonous mushrooms in the world and is responsible for most mushroom poisonings globally. As little as 30g of Death Cap mushroom can be fatal, causing liver and kidney failure in humans and animals if not treated promptly. The Death Cap has a greenish-grey rounded cap, white gills, and a white ring around its stem. It usually fruits in the fall, particularly after rainfall, and can be found growing on many hardwood trees, especially Oak trees.

Death Caps contain a toxin called Amatoxin, or ɑ-amanitin, which is not destroyed by heat. This toxin affects the liver and kidneys, leading to failure and potentially death. There is currently no known antidote for Amatoxin poisoning, and few effective treatments exist. However, in 2023, Chinese and Australian scientists reported a potential breakthrough, discovering that a widely available drug with FDA approval may be effective in countering the effects of Death Cap poisoning. This drug has so far only been proven to work in mice, but it offers new hope for an eventual antidote for humans.

It is important to exercise extreme caution when encountering wild mushrooms, as it can be difficult to distinguish between edible and poisonous varieties. The Death Cap, in particular, can resemble other edible mushrooms in both its immature and mature states, leading to accidental poisonings. In addition to the Death Cap, other deadly mushrooms in the Berkeley area include the Funeral Bell, the Western Destroying Angel, and the Giant Puffball.

The California Poison Control System advises against consuming foraged mushrooms and recommends only eating mushrooms purchased from grocery stores. They receive numerous calls each year regarding human mushroom exposures, with young children being particularly at risk. If you suspect that you or your pet has ingested a poisonous mushroom, seek immediate medical attention from a veterinarian or doctor.

The Western Destroying Angel is another deadly mushroom common in the Berkeley area, thriving after rainfall

The Western Destroying Angel is a deadly mushroom that is common in the Berkeley area. It is one of the most toxic mushrooms known and contains Amatoxins, a set of toxins that are not destroyed by heat. Amatoxins affect liver and kidney function, leading to failure in humans and animals if not treated promptly. As little as 30g of the mushroom is enough to kill a human, and there is no known antidote for its toxins.

The Western Destroying Angel is a member of the Amanita genus, specifically Amanita ocreata, and is found in western North America. It is characterised by its white gills, stalks, caps, and spore prints. The cap can also be yellowish, pinkish, or tan at the centre. The stem has cottony to pearly flakes when young, losing this appearance as it ages. The Western Destroying Angel typically grows on the ground in mixed woods and in grass near trees, and it grows alone or in dense groupings. It can be found in urban and suburban areas but is more common in wooded areas.

The Western Destroying Angel can be mistaken for edible fungi, such as the button mushroom, meadow mushroom, or horse mushroom. It can also resemble puffballs when it is still enclosed in its universal veil. However, slicing it in half will reveal its internal mushroom structures. The Destroying Angel typically fruits from June through November, depending on the region and local weather conditions.

In the Berkeley area, the Western Destroying Angel thrives after rainfall, and pet owners are encouraged to keep their animals under close watch during the winter months, after recent rainfall, and in areas with regular irrigation. The California Poison Control System advises people to use caution and only eat mushrooms purchased from grocery stores rather than foraged mushrooms. They received 33 calls for human mushroom exposures in Alameda County in 2023, with eight of those calls regarding young children aged five and under.

The discovery of new mushroom species on campus highlights the importance of preserving open spaces and healthy vegetation on the urban campus

The UC Berkeley campus is home to a diverse range of mushroom species, with over 200 different types of fungi and lichen. Among these are newly discovered species, highlighting the importance of preserving open spaces and healthy vegetation on this urban campus.

The campus serves as the "type locality" for certain mushroom species, meaning that the representative specimens for these species were collected and identified on campus. This discovery was made possible by DNA sequence analysis, which has revealed that many mushroom species in California and across North America have been misidentified, bearing European names despite being distinct. For example, researchers Vellinga and Nguyen discovered that the California elfin saddles were different from their European counterparts and described two new species from California: Helvella vespertina and Helvella dryophila, the latter being found on campus.

The presence of these unique mushroom species underscores the importance of maintaining the campus's green spaces and healthy vegetation. With approximately 150 species of mushrooms identified on campus, including edibles like chanterelles and porcini, as well as deadly varieties like the Funeral Bell and Death Cap, it is crucial to exercise caution when encountering wild mushrooms. The Death Cap, in particular, is responsible for the majority of mushroom poisonings worldwide, and as little as 30 grams can be fatal to humans.

The discovery of new mushroom species on campus also emphasizes the need for a comprehensive catalog of North American mushroom species. This endeavor is a longtime goal of Professor Tom Bruns from the Department of Plant and Microbial Biology at UC Berkeley. By understanding the diversity and distribution of mushroom species, we can better appreciate the ecological significance of urban green spaces and the potential risks associated with certain fungi.

In conclusion, the discovery of new mushroom species on the UC Berkeley campus draws attention to the importance of preserving open spaces and healthy vegetation within urban environments. These green areas provide a habitat for a diverse range of fungi, contributing to the ecological richness of the campus. Furthermore, by studying these mushrooms, we gain knowledge about potential hazards, ensuring the safety of the community and their pets.

The Bay Area Mycological Society is a group of mushroom enthusiasts based in the East Bay, who meet at UC Berkeley and sponsor local mushroom walks

The Bay Area Mycological Society (BAMS) is a group of mushroom enthusiasts based in the East Bay. BAMS was established in 2006 to explore the art and science of mushrooms. Members include beginners as well as professionals in the field. The society holds meetings at UC Berkeley, where over 200 species of fungi can be found on campus, particularly along the campus creeks.

BAMS organises local and long-distance mushroom walks, or 'forays', and has played a key role in fungal surveys at Point Reyes National Seashore and Yosemite National Park. The society also organises the Point Reyes Fungus Fairs and All California Club Forays, and is affiliated with the North American Mycological Association.

BAMS members can also join a lively online discussion group to learn more about fungi. The society's founder, Debbie Viess, is a retired zoologist with expertise in mushroom poisoning. Viess has written about the dangers of amatoxin poisoning, which affects the liver and kidneys and can be fatal to both humans and animals.

Mushroom enthusiasts in the Bay Area can also join the Mycological Society of San Francisco (MSSF). MSSF was founded in 1950 to promote the understanding and enjoyment of mushrooms and other fungi. The society holds monthly meetings during the local mushroom season (September to May) at the Randall Museum in San Francisco. MSSF also organises an annual Fungus Fair, camping forays, and single-day mushroom walks.

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