North Carolina Botanist Leads Study Documenting Extinct Plant Species

North Carolina Botanist Leads Study Documenting Extinct Plant Species

7:04am Sep 14, 2020
Photo of Franklinia alatamaha, a species extinct in the wild. Photo courtesy of the John Bartram Association/Bartram's Garden.
  • A photograph of the type specimen housed at the Smithsonian Herbarium of Large-flowered Barbara’s-buttons (Marshallia grandiflora). This is the newly recognized extinct plant endemic to two western North Carolina counties (Henderson & Polk). Last collected 101 years ago. Photo credit: Smithsonian Herbarium and image courtesy Wesley Knapp.

  • Image of Nuttall’s Micranthemum (Micranthemum micranthemoides), the intertidal mud flat species once found from New York to Maryland. This is the species that started Knapp's interest in extinct plants. This was the last time this plant was ever seen. Image courtesy Wesley Knapp and the Massey Herbarium, Virginia Polytechnic Institute.

  • Image of the Single-flowered Mariposa Lily (Calocphortus monanthus). Apparently, it was only seen a single time by the botanist, E.L. Greene, who collected the plant in 1876 from California. Described new to science much later on by Ownbey in 1940. Photo credit: Harvard University Herbarium.

A recently published report led by a North Carolina botanist outlines plant extinctions in the continental United States and Canada. The findings show that 65 species are presumed extinct, which is more than any previous study had documented.

The work was led by ecologist Wesley Knapp of the North Carolina Natural Heritage Program. He says it took about five years to compile the new list.


Photo of Crataegus fecunda – the St. Clair Hawthorn. Known from a single individual at the Morton Arboretum. Photo credit: Matt Lobell of the Morton Arboretum.

“Each extinct plant tells its own story and has its own unique circumstances, and we had to vet each species past experts who knew those groups,” says Knapp.

North Carolina has three on the list all from the western part of the state, but the majority of extinct plants are from the Southwestern part of the U.S.

“One thing we found is that 64 percent of these extinct plants were what we call single-site endemics. They are only known from one place in the landscape,” he says.

And that has implications for future conservation efforts, meaning it will be important to focus on small site conservation and habitat management in addition to larger landscapes.

Knapp says 65 plants is likely an underrepresentation of what’s actually gone extinct. Occasionally, plants are rediscovered.  

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