Mushroom Magic at The Huntington

The breathtaking beauty of The Huntington’s gardens owes much to a hidden world beneath your feet. Healthy soil is a complex network of inorganic substances (e.g., minerals, rocks), organic compost that adds nutrients as it decomposes, and a host of tiny organisms. Some are visible to the naked eye, such as isopods (roly-polies), mites, and earthworms. Others, including bacteria, protozoa, and algae, are not. Fungi are vital members of this underground community, balancing nutrients, forming mutually beneficial partnerships with plants, and helping to break down organic matter.

Nearly all land plants depend on fungi. Together, plant roots and fungal filaments (mycelia) form intricate underground networks called mycorrhizae. These fungi extend plants’ access to nutrients such as nitrogen and phosphorus in exchange for the sugars produced during photosynthesis. While fungi remain underground, with favorable conditions they sometimes produce fruiting bodies, or mushrooms, that contain spores, much like seeds. Certain fungi have specific associations, such as chanterelles with oaks or truffles with trees in the beech, birch, and pine families.

Cultures worldwide have long relied on mushrooms for food and medicine, though correctly identifying them can be perilous since many poisonous mushrooms closely resemble edible ones. Even seasoned mycologists (scientists who study fungi) risk mistakes. Foraging for mushrooms should always be done under the expert guidance of someone familiar with local fungi species.

Orchids also form mutually beneficial relationships with fungi. When orchid seed pods open, their dust-like seeds are carried long distances by the wind. They lack endosperm—the nutrient-rich packets in most seeds that sustain developing plant embryos—making them lightweight and easily dispersed. However, without these food reserves, young orchids cannot grow on their own. Instead, they rely on mycorrhizal fungi at their landing site. The fungi provide the nutrients necessary for the orchids’ early development, and as the orchids mature, they fulfill this partnership by sharing sugars produced through photosynthesis.

Fungi are crucial not only for plant growth but also for decomposition. Saprophytic fungi break down dead organic matter, recycling nutrients back into the ecosystem. However, fungi can also cause disease. For example, white pine blister rust requires an intermediate host before infecting pine trees, while Armillaria fungi cause shoestring root rot through direct root contact. Some fungi are spread by insects such as ambrosia or bark beetles, whose larvae feed on the resulting fungal growth. Healthy plants may resist these infections, but weakened plants—particularly those stressed by drought or heat—are more likely to succumb.

Historically, fungi were classified as primitive plants due to their plant-like reproductive cycles. Over time, scientists recognized their animal-like characteristics. In 1969, ecologist Robert Whittaker proposed fungi as a distinct kingdom, now understood to be more closely related to animals than plants. Today, fungi are one of the recognized kingdoms of life, alongside animalia, plantae, and microbial groups.

Efforts to document North America’s 11,000 known species of fungi began in earnest at a Mycological Society of America meeting in 2012 at Yale University. This ambitious vision culminated in the 2017 launch of the North American Mycoflora Project, which evolved into the Fungal Diversity Survey. This initiative engages community scientists to help document fungal biodiversity using platforms like iNaturalist to build a comprehensive fungal database.

Fungi are an essential part of biodiversity at The Huntington, though many species remain unseen without sufficient rainfall. The past two winters’ heavy rains led to a surge in mushrooms across the gardens. Inspired by this fungal activity, Huntington Conservatory technician Rafael Gomez joined Exploring the Mycoverse, a mycology book club organized by Aaron Tupac, a field biologist with the California Fungal Diversity Survey.

In November 2022, Gomez invited Tupac to explore parts of The Huntington’s property that had never been surveyed for fungi. Since then, Tupac has conducted several surveys, collecting more than 40 unique fungal species for the California Fungal Diversity Survey. DNA analysis revealed that many of these specimens do not match records in other databases, indicating that they may be newly documented species.

Key survey sites included oak woodlands near the Ranch Garden and lower canyons at the edges of the property, where water accumulates. The November 2022 survey documented roughly 30 notable fungi species, including several rare ones. Among the discoveries were four native saprophytic species in the Shepherd-Brokaw Orchard and reishi mushrooms (Ganoderma tuberculosum), marking the first record of this Asian species outside Florida and Texas. With winter rains ahead, more surveys are planned.

“Throughout my studies and career—and as the daughter of a mycologist—I’ve come to appreciate how vital fungi are to ecosystems and their relationships with plants and animals,” said Nicole Cavender, Telleen/Jorgensen Director of the Botanical Gardens. “Surveys help us better understand which fungi are present and how we can support biodiversity in human-shaped environments like The Huntington. Documenting these species is key to sustaining a rich variety of life in this unique habitat.”

Sandy Masuo is the botanical content specialist at The Huntington.