Invasive plants take the spotlight in a new exhibit

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The Hall of Botany at the Carnegie Museum of Natural History in Pittsburgh features dioramas of natural plant scenes, some from almost 100 years ago. A spring floral diorama of Pennsylvania’s Laurel Highlands is lush with blooming dogwood trees and yellow trout lilies hugging the forest floor. But that’s not what the same landscape would look like today, in part because of invasive plants.

A new exhibit opened in March at the museum that grapples with that contrast. “Uprooted: Plants Out of Place” looks at the complex histories and language around invasive plants and how they impact ecosystems.

LISTEN to the interview with Mason Heberling

The exhibit includes plant illustrations like this multiflora rose example from the Hunt Institute for Botanical Documentation. Photo: Brandon Slate / CMNH.

In the Hall of Botany, three species are examined through signage, plant specimens, illustrations, historical documents, and sensory exhibits: multiflora rose, stiltgrass, and garlic mustard.

“Oftentimes we point at specific species, maybe we’ll say multiflora rose is so bad, as if this species has some sort of sentience and is out to ruin us,” said Mason Heberling, associate curator in the Section of Botany at the museum. “In fact, when we tell the full story of how it got here and how we are where we are today with our environment, we realize that this was human activity.”

Multiflora rose does leaf out earlier in the spring than native plants in eastern U.S. forests, potentially shading native wildflowers, young trees and shrubs. But it was originally brought to America from Asia in the 1860s as a rootstock for grafting other types of roses.

Heberling said invasive plants are plant species introduced from another area that have an impact on the environment, the economy, or human health.

“So the idea of what is a negative impact is where we kind of get in that a little bit of the gray area between science and society,” he said. “Who decides what plant, in particular, is considered invasive?

Knotweed is commonly called itadori in Japan. But there are over 600 historic words for the plant in Japanese. Photo: Camila Casas / CMNH

While the displays in the Hall of Botany focus on biology and the history of the plants’ introduction, Heberling says the exhibit on the museum’s third floor overlook is more reflective, looking at cultural perceptions around invasive plants and land stewardship.

“One thing that is maybe obvious but sometimes forgotten is that introduced plants are native somewhere and that they have a relationship with not only their native environment, but also the people that live in that native environment,” he said.

One wall features framed herbarium collection specimens of knotweed, commonly known as itadori in Japan, and thought of as an invasive weed in the U.S. In the background, green wallpaper displays some of the over 600 historic Japanese words for knotweed and how people interact with it, like “taro stem and “chin corn.”

: “Itadori at old Pittsburgh Brew Works site” by Koichi Watanabe

: “Itadori at ruins of Osaka Castle in Osaka, Japan” by Koichi Watanabe

Two pieces upstairs, commissioned for the exhibit from photographer Koichi Watanabe show knotweed’s range. One photo depicts a wild patch flourishing along a brick wall at the old Pittsburgh Brew Works. Next to it, a photo shows itadori growing through the cracks at the ruins of Osaka Castle in Japan.

Mason Heberling is the associate curator in the Section of Botany at Carnegie Museum of Natural History. Photo: Kara Holsopple / The Allegheny Front

A video display also features local Pittsburgh groups, like Allegheny Goatscape and Garfield Community Farm, which are attempting to holistically handle invasive plants on the landscape.

Visitors are encouraged to think about invasive plants that might be in their gardens by a colorful display of blooms, and to take a plant tag to learn more about common and popular invasive species like butterfly bush and English ivy.

The exhibit will be open through the next year.