MONACA, Pa. — There’s a long-standing debate in the wild ramp community, with one faction arguing that there is only one species of the plant, while others maintain there are up to four species.
Now, a team led by researchers at Penn State Beaver have provided the first genetic evidence supporting a second species of ramps.
They published their results recently in PLOS One.
Ramps, or wild leeks, are plant native to the forests of eastern North America and look similar to green onions but taste like garlic. Ramps are highly sought after in certain areas and are popular with foragers and with chefs who like to use locally sourced food. This popularity has led to overharvesting in some areas.
Ramps belong to a large umbrella group called Allium, which includes many other plants including onions and garlic species. Prior research by other scientists had investigated the potential of two specific ramp species, but concluded that only one, Allium tricoccum, existed. According to Penn State Beaver Associate Professor of Biology Sarah Nilson, there has been confusion over how to identify the two species, which has led to uncertainty about how many species there are.
“There has only been one other genetic study on ramps, and the tools used then were not high-enough resolution to identify the differences we found,” Nilson said, explaining her group employed “microsatellite markers” in their analysis.
These markers consist of repeating genetic sequences and are easily identifiable in laboratory tests. Researchers can extract and process the DNA from sample plants to reveal where these markers appear in the sequences, Nilson said. As opposed to comparing the billions of paired bases that make up DNA, comparing the markers allow the researchers to more quickly identify genetic differences, she said.
Nilson likens to the genetic comparison to comparing two books with the same titles and covers. Instead of reading both books and highlighting every difference and similarity, a person can compare the table of contents to assess variability, she said.
Nilson said they found enough genetic variability in the samples to support the existence of a second species of wild ramps, called Allium burdickii. The Allium burdickii samples were genetically distinct from Allium tricoccum samples, even when the samples were collected at the same location.
Nilson said the discovery was largely possible because she lives and works in southwestern Pennsylvania, where she collected the initial Allium burdickii samples. So far, Allium burdickii has only been found in southwestern Pennsylvania and states to the west.
“I live and work here, and I was able to do more fieldwork here, and we found it here,” Nilson said. “That’s the importance of having faculty all over the state. When you’re actually rooted in a place, you know it better.”
Additionally, the researchers found that there were differences in the amount of genetic variation between the species and among populations within species.
The finding, Nilson said, could help better support sustainable harvesting and land management to preserve the plants. She explained that ramps are not only of culinary importance, but the foraging of ramps is culturally important to certain indigenous groups and Appalachian communities.
“We understand the cultural importance of these plants, and we want to be able to protect the practice of harvesting for those groups,” Nilson said.
A driving factor of overharvesting is that ramps are among the first plants to emerge in the early spring when there is a dearth of fresh produce, and everyone is excited to have it on the menu, Nilson said. Harvesters take the entire plant, including roots, because chefs will use it all. However, that’s a problem as it takes ramps seven years to fully grow.
Nilson recommended people only harvest what they need and wait until ramps have fully sized up before harvesting. She said ramps are easy to grow if they have enough water and a site in a shady forest area, so planting new ramps can help in conservations efforts.
“We’re not anti-foraging,” she said. “We’re encouraging education about more sustainable harvesting and waiting to harvest.”
Nilson’s research is an extension of work she began in 2018 when she was awarded a research grant by the Pennsylvania Department of Conservation and Natural Resources to determine if ramps are a vulnerable species.
Co-authors on this study include Eric Burkhart, teaching professor in ecosystem and science management at Penn State; Malia Costa, who graduated with a degree in biology from Penn State Beaver in 2023; Matt Estep, associate professor of biology at Appalachian State University; and Harvey Ballard, a professor of environmental and plant biology at Ohio University.