Science Café at Stetson: Native Plant Designation

In the Gillespie Museum’s second Science Café at Stetson University this spring semester, Jason Evans, Ph.D., assistant professor of Environmental Science and Studies, will consider “What is Native Anyway? The Strange Tale of Water Lettuce in Florida.” His talk is scheduled for Thursday evening, March 19, at 7 p.m. in the Gillespie Museum, Stetson University, 234 East Michigan Avenue, DeLand.

Scientific illustration of Pistia stratiotes L, from Conservation & Society
Scientific illustration of Pistia stratiotes L, from Conservation & Society

Pistia stratiotes, pictured right, commonly known as water lettuce, is a conspicuous floating plant that for several decades has been listed and managed as a Class 1 invasive non-native species throughout the State of Florida. “Given this background, many people are surprised to learn that there has never been firm scientific consensus that water lettuce is non-native to Florida,” explains Evans. “The most current evidence, in fact, very strongly indicates that the species has been present in Florida for at least 12,000 years.”

In his Science Café, Evans will give a critical history of this controversy that integrates various aspects of water lettuce biogeography, ecology, and history in Florida. This trip necessarily takes us into the ballasts of colonial Spanish ships, the travels of William Bartram, the “Vero Man” archaeological site, and the late-Pleistocene sediments of southern Florida’s Lake Annie. However, detours such as the 1884 World’s Fair, phytophagous insects in Argentina, the Nile River during the time of the ancient Romans, and Aryuvedic medicine further help to round out the story.

An international movement, Science Cafés promote scientific literacy by encouraging relaxed, open conversations among scientists and nonscientists of all ages. “Our spring series provides some

"Water Lettuce, Florida, 1765" Drawing by William Bartram: http://plants.ifas.ufl.edu/images/pisstr/bartram
“Water Lettuce, Florida, 1765” Drawing by William Bartram

informal evenings with the university’s faculty in environmental science,” says Museum Director Karen Cole, Ph.D. On Thursday, April 16, department chair Wendy Anderson talks of her research in coastal ecosystems in “Too Much of a Good Thing? Impacts of Seabirds and Their Predators on Island Ecosystems and Other Coastal Areas.”

These events are free and open to all. Cultural credit is available to Stetson undergraduates. For more information, contact the Gillespie Museum (386.822.7330 or [email protected] ) or visit the museum’s website www2.stetson.edu/gillespie.

(“Water Lettuce, 1765” is from http://plants.ifas.ufl.edu/images/pisstr/bartram.jpg)