Where Do Morel Mushrooms Grow in Northern California?

Where can I find morels in the Bay Area?

With a wet winter and a damp spring this is turning out to be a relatively good year in California for finding one of the most sought after edible mushrooms in the world: the morel. There are many places to find morels in the Bay Area and understanding these organisms is key to having a chance at seeing them.

The common name “morel” refers to mushrooms of the genus of Morchella that encompasses 100 or more species worldwide. California contains at the very least 10 species and the nitty gritty of the taxonomy is still being figured out for a number of our local species. Morels are taxonomically very different than most of the mushrooms encountered on local trails or even in local super markets in that they are part of the the Ascomycetes, a division of fungi named after their sac-shaped spore-bearing cells. The majority of mushrooms you find in the grocery store or in the woods are Basidomycetes which have club-shaped cells that spores bud off of. These features are microscopic, but in general if it is shaped like a cup or like a cup folding up on itself, very intricately in the case of morels, it is an Ascomycete, while all the mushrooms with gills, pores, and teeth beneath their caps are Basidomycetes.

Morels are most common in warm weather and where there is easy access to moisture. The mushroom is just the fruiting body of the fungus and usually only occurs once a year when conditions are favorable to spread their spores. The rest of the year the fungus hides out in harder to recognize forms; hyphae and mycelium that just appear like white threads running through wood chips or soil. Depending on the species, the right mix of temperature and moisture will occur at different points during our spring and even summer months.

Usually the earliest morel on the scene is Morchella rufobrunnea, and it is also the easiest to find in the Bay Area. It is commonly known as the “blushing morel” or the “wood chip morel” due to its proclivity to spring up in mulched areas and its pale color with sometimes pinkish tones after being handled. They can occur as early as January if we get a few warm days and can be easily scouted in woodchip landscaping all the way into late May. They are only slightly dependent on the weather as more often than not their preferred habitat gets watered by landscape irrigation. M. rufobrunnea was the first morel mushroom ever grown in cultivation, and this is only because it is one of the few morels that is saprotrophic — it grows off of decomposing organic matter and not in association with a live plant. Ronald Ower, who patented a process for growing morels in 1985, lucked out in that the morels he started working with came from specimen he picked up in San Francisco planter box.

Another morel found in urban mulched landscaping is Morchella importuna. It shows up a little later and has overall a much darker complexion. It can also be found in local disturbed areas such as trail cuts where roots are present, and in recently burned areas where it feasts on available wood. The majority of cultivated morels that come from China are M. importuna since, like M. rufobrunnea, it is a saprobe.

The morels that grab the headlines in California are usually the burn morels. These morels are most present in years after a fire has ravaged an area with coniferous trees, especially firs. It is still unclear as to the full relationship between the morels and conifers. Is it a symbiotic relationship and when the tree dies the morel sends up fruiting bodies to find find a new host? Or is the role of the morel a little more self-centered and it’s just feeding off of the trees as they die? Usually fires close to the Bay Area don’t produce morels, because they aren’t the right mix of trees, but the Valley Fire and a few others that burned up in elevation to to conifer forests have produced morels. Burn morels occur in the biggest numbers the spring after the fire and occur each year after, dwindling in numbers each year.

The morels that don’t grab the headlines and are the most sublime to see in the spring are the ones that don’t like the urban landscaping or the post-apocalyptic firescapes, but enjoy lush green wooded areas. Morchella americana, a striking light colored morel, inhabits stands of cottonwood trees. Morchella tridenta or a similar species can occasionally be spotted around madrone and manzanita in the early spring.

If you desire to not only feast upon them with your eyes, but also with your stomach there are some cautions to take heed. Morels found in human landscapes have been shown to concentrate some heavy metals. Urban morels also accumulate pet urine, exhaust, and other city debris to their exterior. Most parks and reserves in the Bay Area do not allow you to collect fungi from their premises. Morels have some lookalikes to beginners; Verpa, Helvella, and Gyromitra, the latter of which has potentially poisonous species in our area. Morels also are one of the most frequently reported mushrooms causing poisonings, mainly due to undercooking.

Ask the Naturalist is a reader-funded bimonthly column with the California Center for Natural History that answers your questions about the natural world of the San Francisco Bay Area. Have a question for the naturalist? Fill out our question form or email us at atn at baynature.org!