Stalking the wild Begonia

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Portrait of Dr. Mark TebbittSenior Sara Gmutza adjusts the scanning electron microscope in Frich Hall, bringing a tiny begonia seed into focus. Magnified 100,000 times, the barely visible speck is revealed as a prickly orb. She notes its distinct texture, takes a photo and adds the black-and-white print to a stack of snapshots. 

Gmutza, a wildlife biology major, is the first person ever to examine these seeds gathered high in the Andes mountains.

They were brought to Cal U by Dr. Mark Tebbitt, an assistant professor in the Department of Biological and Environmental Sciences.

In January, Tebbitt conducted botanical fieldwork in central Bolivia under a grant from the American Begonia Society.

Working with researchers from the Noel Kempff Mercado Museum of Natural History in the city of Santa Cruz de la Sierra, he discovered five&species of tuberous begonias entirely new to science, plus four natural hybrids.

“I’m a plant systematist,” Tebbitt explains. “My research focuses on how to identify species, how they evolved, how they are related, and how they interact with pollinators and disperse their seeds.” 

For about five years Tebbitt has been investigating a little-known group of South American begonias. Unlike most species, which thrive in humid tropical rainforests, these begonias grow on sunny cliffs alongside cacti and other succulent plants in the mountains of South America.

“We were targeting new species, and we found new species,” he says.

“The next step will be to name them and sequence their DNA.”

Working with scientists from the Royal Botanic Gardens Edinburgh and the Universidad de los Andes Colombia, Tebbitt aims to show how these new plants are related to the more than 1,500 species in the genus Begonia. 

The work has practical value for plant conservationists, too. 

“This area of the Andes is rapidly changing, and plant species are becoming extinct,” says Tebbitt, whose next research trip will take him to Peru. 

“If the plants don’t have names, we can’t catalog them. Knowing what’s there is the first step toward conservation efforts.” 

Complete collections of Tebbitt’s finds were placed in the herbariums at the museum in Santa Cruz, Bolivia, and Missouri Botanical Garden in St. Louis.

A doctoral student in Bogota, Colombia, is sequencing the plants’ DNA. To learn more about how the begonias are pollinated, Tebbitt will grow them in his outdoor research collection this summer.

Most begonias are pollinated by bees or wasps, he says, but one species may rely on hummingbirds. His Cal U colleague Dr. Carol Bocetti, also of the biology department, will use gauzy “mist nets” to snare hummingbirds that visit the blooms. He hopes that pollen collected from their beaks and bodies will help to verify their role as pollinators. 

Meanwhile, Gmutza is busy scanning, photographing and measuring the seeds of about 50 begonia species.

“I’m amazed by the intricacy of the seeds — they’re really pretty to look at,” she says. “It’s fascinating to see the different species and how they vary.”Bogonia information with photo.

Gmutza and Tebbitt plan to publish a paper based on their research.

Gmutza’s careful observations and measurements provide taxonomic information that will help to classify the newly discovered plants. The magnified images she produces with the scanning electron microscope reveal structures invisible to the naked eye — clues to how the seeds are dispersed in the wild. 

“It’s wonderful to be able to do this research as an undergraduate,” says Gmutza. “I’m thinking about graduate school, so this is a great opportunity.