This Pacific Northwest delicacy is one-of-a-kind. Now it has a name — and science — to back it

The rich, earthy mushroom known for adding a sublime finishing touch to a dollop of whipped cream, a bubbling dish of fondue or a steaming plate of pasta just got a little fancier.

The Oregon black truffle – which can fetch up to $800 a pound – is now a unique species, further distinguishing the aromatic fungus from its European counterparts.

Please call it Leucangium cascadiense – named for its now-proven Cascade roots.

The distinction is more than a pretty name.

Before now, biologists believed the Oregon black truffle was the same as the Leucangium carthusianum, grown in Poland, Greece and Italy and originally found under pine trees in France.

A new study published in the scientific journal Persoonia found that not only does the Oregon black truffle grow exclusively in the Pacific Northwest, but it also grows specifically on Douglas fir trees – exciting news in the mycology community.

“I hope that people will appreciate more that there’s a lot going on underground beneath their feet that we didn’t really know about before,” said fungal biologist Ben Lemmond, the study’s lead author.

The study also discovered two other new North American truffle species – found in the eastern U.S. – and one new species combination, and the researchers elevated one variety of truffle to a species, Lemmond said.

The findings help paint a clearer picture of the fungal family tree. Understanding how many different species exist, where they are and how they function helps scientists understand how ecosystems work and how species interact, which can fuel conservation efforts, Lemmond and other researchers said.

“Truffles and all fungi can be used to ask some really cool questions about the world,” said Jessie Uehling, an associate professor in Oregon State University’s botany and plant pathology department.

“How is biodiversity distributed across our planet?” said Uehling, who wasn’t involved in the study. “How many species of fungi are out there in the world, and when we find a new one, what does that mean for the picture that changes?”

Less clear is the impact the news could have on the culinary scene and the competitive truffle industry.

The Oregon black truffle is popular regionally, but trails in fame behind its old world French and Italian cousins. It’s unlikely that the scientific findings will help the species break into fine-dining kitchens across the country, but it can’t hurt to have a distinctive claim on a delicacy.

“In this world where Japanese fish is flown in from Tokyo overnight and can be on the sushi counter in New York the next day, it’s kind of wonderful to have something that is so specific to a place and seems to not want to leave that place,” said Pete Wells, the former New York Times chief restaurant critic.

Wells visited Oregon earlier this year for a feature on the hunt for these “stinky, fussy” treasures. His favorite dish, he said, was Leucangium cascadiense-infused ice cream at a dinner in Eugene.

What is a truffle, anyway?

Truffles generally resemble small rocks or clumps of dirt and evolved from above-ground mushrooms, which spread their spores through the air.

They grow underground, emitting a fragrant aroma – detectable from 20 feet away – to attract animals to dig them up and spread their spores, said Charles Lefevre, the president of New World Truffieres, an Oregon-based truffle harvesting and growing company that ships truffles and trees throughout the U.S.

Thousands of truffle species grow worldwide and 300 in Oregon alone, Lefevre said. But only four Oregon species are considered gourmet edibles: the winter white (Tuber oregonense), spring white (Tuber gibbosum), the Oregon brown truffle (Kalapuya brunnea) and the newly named Leucangium cascadiense.

The Oregon black truffle is in the Morchellaceae family of fungi, related to morel mushrooms, while most other edible truffle species are in the Tuberaceae family.

While some of those tuber varieties offer garlicky, savory notes, Leucangium cascadiense contains fruity characteristics ranging from “green apple to strawberry to banana to pineapple to mango,” Lefevre said.

As Oregon black truffles mature, they develop more nutty, savory undertones, with notes of blue cheese, parmesan and ultimately “the smell of a pile of freshly fallen leaves,” he said.

Oregon truffles have been recognized for their taste and smell since they were first harvested around 50 years ago, said Lefevre, who has worked for years to elevate the regional species to the same international status as European ones, largely through the annual Oregon Truffle Festival.

The Oregon black truffle’s fruitiness means it shines best in desserts, said Charles Ruff, the festival’s culinary director. He’s served it in, for example, hot chocolate or cake icing. Meanwhile, European Tuberaceae truffles – a centuries-old culinary tradition – are typically grated over dishes such as pasta or omelets (though recipes also call for the Oregon black truffle’s use on main courses).

Pacific Northwest roots

The study’s researchers used sophisticated computer programs to analyze the DNA sequences of many different truffle species, including Oregon black truffles and Europe’s Leucangium carthusianum.

The team confirmed that although they look similar, they’re genetically “very distinctly separated,” Lemmond said.

The researchers examined fresh truffles they obtained from trips to the Pacific Northwest, truffle spores found in mammal scat samples and dried specimens from fungal collections at various institutions, Lemmond said.

Some of the samples came from the herbarium at Oregon State University, a hub for fungal biology and home to the world’s largest truffle collection. Others were harvested by study co-author Heather Dawson’s truffle-trained golden retrievers, Rye, Pyro and Cricket.

The study confirmed that Oregon black truffles behave like other truffles. They are ectomycorrhizal, forming symbiotic mantles around tree roots, said Dawson, a Ph.D. candidate at the University of Oregon. That was unclear before now because of their close relation to morel mushrooms, which don’t always depend on symbiosis with trees.

The scientists also determined that the state’s black truffles share a key relationship with one type of tree in particular – another Oregon staple, the Douglas fir.

The mushrooms latch onto Douglas fir root cells, feeding off the trees’ carbon and sharing their own nutrients, including nitrogen and phosphorus, Lemmond said.

“That’s really crucial, because it tells us that’s how it gets its energy,” said Lemmond, who was working on his Ph.D. in the University of Florida’s plant pathology department during the four-year study, but is now a postdoctoral researcher in plant and microbial biology at the University of California, Berkeley.

While other truffle species – including the Italian white truffle or Périgord black truffle, world-renowned for their culinary use – grow on various tree species around the world, the Oregon black truffle is predominantly associated with Douglas firs, the study found, though Lemmond said it’s possible they could occur on other pine trees.

Culinary cachet

The research could aid future cultivation efforts, as Oregon black truffles haven’t yet been planted and grown, Lemmond said.

Doing so would require mixing the fungus with water to create a smoothie of truffle spores, then pouring that over a Douglas fir seedling, planting it and waiting around four to 10 years, he said.

For now, though, hobbyists and commercial harvesters continue to use truffle-hunting dogs to sniff out the wild mushrooms where they’re naturally abundant in the state’s forests. Then they’re often peddled to restaurants.

The genetic discovery and species name change help make it clear that Oregon has something no one else has, said Lefevre, of New World Truffieres. His company harvests Oregon truffles and cultivates European ones.

“On some level, Oregon is the place that has it all,” Lefevre said. “At least when it comes to truffles.”

But whether that individuality will translate to more cachet on a dinner menu remains to be seen.

Rowan Jacobsen, the author of the 2021 book “Truffle Hound,” isn’t convinced that the findings, while fascinating, will change much for restaurateurs – much less for those taking a bite.

“I can’t see it having any effect on the culinary scene,” Jacobsen wrote in an email to the Oregonian/OregonLive. “Most people eating truffles could barely tell you what a truffle is!”

Wells, the former Times food critic, said he doesn’t think the study will make ripples in restaurants. The Oregon black truffles still have a short shelf life that so far has limited their distribution and use.

Their prime lasts only for about a week, so they seem to demand to be eaten near where they’re dug up, said Wells, who during his visit tasted fresh truffles hours after they were pulled from the ground.

The Oregon black truffles tasted “vastly different” from European varieties Wells had tried before, he told the Oregonian/OregonLive.

He noted sweet undertones and tropical aromas – not that they tasted like real fruit, he said, but rather offered a beguiling, incomparable flavor: “The last thing you expect to be pulling out of the roots of a Douglas fir in the Pacific Northwest.”

Proving a degree of separation from other truffles may be the best result of the study for connoisseurs and biologists alike.

“The more people understand how different and unique the Oregon truffle is,” Wells said, “the better it is for the Oregon truffle.”