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The Plant Detective

Story by
Nancy Joseph

As a child, Jeff Benca was fascinated by dinosaurs. By his teen years, plants were his passion. Now Benca, a UW senior majoring in biology, has combined his interests in plants and prehistory through the study of lycopsids, the world’s most ancient vascular plants alive today. 

Fossil records indicate that lycopsids, or club mosses, date back around 415 million years and have survived multiple extinction events. They evolved roots, leaves, and even a mode of reproduction (analogous to seeds) independent of all other plants. Recent studies suggest that they may even have an entirely novel photosynthetic pathway. By studying both lycopsid fossils and living specimens, Benca hopes to learn how these plants have evolved and persisted over time. 

Jeff Benca with huperzia, one of the club  mosses he cultivates in the Botany  Greenhouse.

Jeff Benca with huperzia, one of the club mosses he cultivates in the Botany Greenhouse.

“I’m using the plants as a tool to look at mass extinctions and climate change,” says Benca. “These plants survived all of the mass extinctions and we don’t know why. If we can expose them to different theorized climatic conditions, we can get a better idea of what might have happened and what we can rule out right away.”

Scientists know, for example, that there have been major climatic changes in the past, when lycopsids were prominent components of Earth’s ecosystems. By placing live club moss specimens under different temperature regimes, Benca hopes to observe whether their leaf shape changes in response to temperature, and whether those changes mimic what is found in fossil specimens—a possible clue to what paleo-temperatures may have been. “Scientists have been using computer models to hypothesize about past climate change during extinction events,” explains Benca. “This could be a way to test those hypotheses and see which ones are more likely than others.” 

Benca has always had big plans for lycopsids, but there’s been a problem: the plants are becoming increasingly rare in some regions due to habitat destruction, overharvesting, and climate change. “Many species live in high cloud forests in the tropics, which are fragile and sensitive ecosystems” explains Benca, who also finds examples in the Washington Cascades. “Some take fifteen years to grow two inches. As their habitats are destroyed, we’re losing entire populations left and right. Every species of club moss native to the United States has been appointed to some rank within the USDA’s ‘protected status’ in at least one state, yet there’s been little effort, besides monitoring programs, to protect them.” 

Benca’s solution? Grow the plants himself. In the past three years, he has built up one of the most extensive teaching and research collections of living lycopsids in the United States—all at the UW’s Botany Greenhouse. For several of the species, it is their first successful cultivation anywhere in the world.

“People hate trying to grow native species because they often die slowly in cultivation,” says Benca. “They’re finicky. But once you know the general principles of what they like, they grow like crazy. It took me about three years of growing these plants and killing them to figure out that they thrive on high humidity, excellent air circulation, and really lousy soil. That soil is like gold to them. Now they’re taking over the Greenhouse.” 

Benca is currently collaborating with colleagues at the Montgomery Botanical Center and James Cook University in Australia on a paper about cultivation and propagation methods for club mosses. Other academic greenhouses and botanical gardens are taking note –and samples. Benca has supplied plant material to the San Francisco Botanical Garden, and will soon provide samples to the Atlanta Botanical Garden and the academic greenhouse at Binghamton University in New York. He hopes to share with more institutions in the future. “The collection is gaining a national reputation, helping place the UW Botany Greenhouse on the map as a resource for ancient plants,” he says.

In addition to expanding the Botany Greenhouse’s collection, Benca also serves as a docent for the facility, leading tours for school groups and others. It’s a role he relishes, believing that the Greenhouse is “a great untapped resource” for the UW and the surrounding community.

“When I was looking at colleges, the Botany Greenhouse was definitely the biggest selling point for coming to the UW,” he says. “It’s really one of the top greenhouses in the country. I felt very lucky to find it.”

For all his contributions to the campus community and the Puget Sound community, Benca was awarded the George and Barbara Akers Scholarship in 2010. While thrilled to receive the award, Benca insists he’s just doing what he loves.

“I don’t consider any of this work,” he says. “I love it. It’s just fun.”