Dr. Aaron Floden
Assistant Scientist, Flora of Missouri

When Aaron Floden first started collecting plants, he purposefully chose a geographic area with low collection numbers. In fact, the 498 square mile area only had about 300 documented species. By the time Floden finished, that number surpassed 1,500 species, including seven species not previously known to the state and two, possibly three, that had never been described.

Such vast discovery may conjure a picture of Floden collecting in a remote, little explored location. But in reality, he was in Campbell County, Tennessee, about an hour north of Knoxville. “People think everything has been discovered in North America, but it really hasn’t,” Floden says. “Some of these places didn’t have roads 40 years ago…and not many people have the time to hike for five to six days out in the middle of nowhere to find little tiny habitats with weird geology.”

The part of Campbell County where he was collecting happened to be one of those places “with a really strange flora and a lot of really rare plants.” It was also one of the first places he collected after moving to Tennessee to study ecology after taking an indirect path to the world of botany.

From Fauna to Flora

Floden, Assistant Scientist at the Missouri Botanical Garden, has always been interested in science, but as a kid he was more intrigued by animals than plants. Growing up, he rescued blue jays and rehabilitated raccoons. He had a collection of reptiles. At one point, he even had a pet opossum.

He first became intrigued by plants when he worked as a chef in a small trattoria at a hotel in Italy right after high school. His dad, who was in the Air Force, had stayed in the hotel for six months at a time during the Bosnia conflict, and the owners eventually asked him if he would like a spot for his son to work in the restaurant.

Spending four months in Italy, and exploring the mountain landscape, was life changing for Floden. “Seeing the plants in the wild there, it was a whole different world.” It encouraged him to start propagating more plants on his own. But when he started college, he began studying engineering.

Through serendipity, Floden ended up in botany. The professor for his biology for non-majors course was a botanist. After the first day of class, Floden talked to the professor about a specimen he had found that could be an undescribed species of the genus Dirca. Over the weekend, Floden went back to Kansas City and collected a few branches from the plant and brought it to his professor. Through the guidance of his professor, Floden conducted molecular work on the plant, and discovered it was, in fact, a new species, which he later described as Dirca decipiens.

Research on the Road

From there, Floden delved deeper into botany. He performed field work in Arkansas, finding two more wild sites for the Dirca decipiens. He then moved to Knoxville where he earned his bachelor’s degree in ecology and evolutionary biology and his PhD in ecology, evolution, systematics, and population biology at the University of Tennessee, Knoxville.

He took more fascinating field trips, finding populations of species that had been found many years ago but largely forgotten since, and new species like Clematis vinacea and Monarda austroappalachiana. “They had all been collected before, frequently; people had just overlooked them.”

One survey taken on 100 acres of property in Hamblen, Tennessee proved especially fruitful. The property owners had reached out about a unique Trillium growing on the property. Floden and a team spent a day surveying the property, which the owners thought had maybe a dozen or so of the Trillium, and they estimated more than 5,000 plants of this undescribed species of Trillium.

“Trillum is one of those genera that is relatively common in gardens,” Floden explains. “It’s very well studied, especially in the Southeast,” which made it even more surprising to find a new species in Tennessee.

Floden’s work isn’t just limited to North America. He’s spent time collecting in Asia, and says some of his best moments have been overseas. He remembes one trip to India where an early monsoon season forced his group to completely reroute their planned expedition. The change ended up being beneficial—he discovered five undescribed species of Polygonatum in one hike. “It was just pure chance that we happened to pick that place.”

Helping the Garden Grow

For the Missouri Botanical Garden, Floden has worked extensively on the Flora of Missouri, helping rewrite keys to reduce the large, multiple-volume Flora to a field guide.

He officially joined the Garden’s staff in early 2017, and cites its international focus on systematics and conservation as a big draw for him. “Everywhere I’ve been overseas when I mention I’m a botanist, I can mention Missouri Botanical Garden and they know what that is.” That isn’t usually the case with universities, Floden adds.

Floden is continuing his work on Flora of Missouri, and his work on the phylogenetics of Trillium is expanding to now include the showy-flowered pedicellate Trillium. He is also pursuing systematic work on several undescribed Monarda, and is involved in wide variety of other projects including studies on various plant species in North America and Asia.

Catherine Martin
Public Information Officer