Researchers discover new types of truffles at Arnold Arboretum
There’s scarcely a more studied patch of soil in New England than the Arnold Arboretum , but it turns out the institution’s trees have been keeping a secret: The roots have been hiding at least eight kinds of truffles, elusive fungi that can carry earthy, funky flavors prized by chefs.
In a recently published paper, researchers wrote that they had identified a new species of the aromatic underground fungus, naming it tuber arnoldianum, in honor of the Harvard arboretum.
They also wrote that they had found evidence the tuber borchii, an aromatic bianchetto truffle, was growing wild there, something they’ve never seen the valuable European species do in North America.
“In this place where people thought there were no truffles, we documented eight species,” said Matthew E. Smith, a coauthor of the paper, published in June by the journal Mycorrhiza. “There’s so much hidden biology in a place that you would expect to know a lot.”
The region’s gourmets might want to temper their excitement before breaking out the shavers and truffle-sniffing pigs, however.
Smith, a fungal biologist at the University of Florida, noted that researchers didn’t find the edible bianchetto truffles — only their genetic information. And he was skeptical that the arboretum’s namesake species would be good to eat; its fruits are small, and its relatives aren’t very tasty.
New England’s acidic soil, harsh winters, and year-round precipitation are “not optimal for truffles,” he added. At least, not the European varieties that people usually eat.
Rosanne Healy, lead author of the paper, gathered the truffles at the arboretum while she was there as a postdoctoral researcher at Harvard and recipient of a 2013-2014 Sargent Award for Visiting Scholars. She said she never even tasted the tuber arnoldianum.
“For me, the truffles are more valuable to keep as specimens for study,” she said in an e-mail. “There weren’t usually enough collected to be tempted to sacrifice a few for tasting.”
In the paper, researchers said their findings add to the knowledge of what comes along with trees when they are transplanted from far away.
Many were brought to the arboretum before a 1921 ban on importing trees with soil and roots intact, and the results provide a glimpse of what that does to the system of symbiotic fungi that exchange water and nutrients for carbohydrates from trees’ root systems.
The study said some of the fungi probably travelled to the United States along with their host trees, while others, like the new species, are native. Tuber arnoldianum “is an aggressive colonizer of native as well as non-native hosts and may have utility in forestry and restoration,” the paper said.
Faye M. Rosin, director of research facilitation for the Arnold Arboretum, said there has never been a fungus named for the institution, though there are several varieties of plants that carry its name.
The paper’s findings struck her with a sense of wonder at a new discovery in a place where there are dozens of scientific research efforts underway at any moment.
“It’s amazing that in this day and age we’re still discovering new species,” she said. “It’s extra exciting that it happened in an urban area, in an arboretum where anyone can go.”