Viburnum: A Starring Role in Science

Viburnum farreri leaves flaunting thick, verdant new growth this spring.

The next time you treat yourself to a walk through the inviting grounds of UW Botanic Gardens, take a moment to appreciate that the flowers and trees play an important role in scientific research–with implications for plants and research institutions all over the world.

“We get requests for plant materials from researchers and institutions about 10 times a year,” reports Raymond J. Larson, M.S., UW Botanic Gardens Interim Director and Curator of Living Collections and the Otis Douglas Hyde Herbarium. UW Botanic Gardens is recognized as having one of the top five collections of woody plants in North America–thanks in part to our temperate climate which graces us with an enviable ability to grow a far-ranging variety of species.

“We are especially valuable because we keep detailed records from the time we receive seeds, cuttings or plants–as well as their condition and life cycle (seed, flowers, time of new growth, size, etc.) throughout their life,” he explains.  “Researchers appreciate our well-documented collections. They’re confident that they’re getting the correct species and will have as much information as possible about origins and how they grow in the ground.”

Recently, the University of Tennessee asked UW Botanic Gardens for samples of Viburnum farreri (common name: fragrant viburnum) as part of a larger viburnum study.  Viburnum farreri is a late winter-blooming species native to China and beloved for its intense fragrance. Not surprisingly, UW Botanic Gardens has one of the continent’s best viburnum collections.

Larson worked in tandem with Pacific Connections Horticulturist Joanna Long to take cuttings of V. farreri from the Witt Winter Garden at the Washington Park Arboretum. “It’s often helpful to have someone taking down the information while the other person collects,” he says. The samples were placed in damp paper towels, enclosed in Ziploc®️ bags, and shipped overnight to Knoxville.

The well-travelled leaves from UW Botanic Gardens and five other arboreta were dried and flash-frozen by the University of Tennessee researchers. Sophisticated genomic sequencing was then performed, gleaning new genomic data which is useful to estimate genetic diversity within V. farreri.  The study will also be helpful in clarifying relationships between members of the Viburnum genus. The findings were published in the scientific journal Plants and can be read here https://www.mdpi.com/2223-7747/10/3/487.

“We don’t just grow plants for beauty and landscape value,” Larson points out. “Botanic gardens such as ours are the arks or zoos of the plant world. We have an important role advancing plant research, and in conserving and preserving the wealth of species that are found throughout the temperate climates of the world. Having a well-documented, well cared-for plant collection helps ensure species survival and the potential for reintroduction.”

Viburnum farreri (center) lives in the Witt Winter Garden, Bed K, on the border between Grids 34-1E and 34-2E