Article

Wang, C., Z. Yap, P. Wan, K. Chen, R. A. Folk, D. Z. Damrel, W. Barger, et al. 2023. Molecular phylogeography and historical demography of a widespread herbaceous species from eastern North America, Podophyllum peltatum. American Journal of Botany 110. https://doi.org/10.1002/ajb2.16254

Premise Glacial/interglacial cycles and topographic complexity are both considered to have shaped today's diverse phylogeographic patterns of taxa from unglaciated eastern North America (ENA). However, few studies have focused on the phylogeography and population dynamics of wide‐ranging ENA herbaceous species occurring in forest understory habitat. We examined the phylogeographic pattern and evolutionary history of Podophyllum peltatum L., a widely distributed herb inhabiting deciduous forests of ENA.MethodsUsing chloroplast DNA (cpDNA) sequences and nuclear microsatellite loci, we investigated the population structure and genetic diversity of the species. Molecular dating, demographic history analyses, and ecological niche modeling were also performed to illustrate the phylogeographic patterns.ResultsOur cpDNA results identified three main groups that are largely congruent with boundaries along the Appalachian Mountains and the Mississippi River, two major geographic barriers in ENA. Populations located to the east of the Appalachians and along the central Appalachians exhibited relatively higher levels of genetic diversity. Extant lineages may have diverged during the late Miocene, and range expansions of different groups may have happened during the Pleistocene glacial/interglacial cycles.ConclusionsOur findings indicate that geographic barriers may have started to facilitate the population divergence in P. peltatum before the Pleistocene. Persistence in multiple refugia, including areas around the central Appalachians during the Quaternary glacial period, and subsequent expansions under hospitable climatic condition, especially westward expansion, are likely responsible for the species’ contemporary genetic structure and phylogeographic pattern.

Joseph William Adams

March 02, 1906 – October 22, 1986

United States

Rosaceae

Collected Rosaceae and identified Salicaceae

Mac Alford
Mac Alford

United States

Asteraceae

Collected Asteraceae and identified Salicaceae

Harry Ardell Allard

January 28, 1880 – February 25, 1963

United States

Cladoniaceae

Collected Cladoniaceae and identified Cyperaceae

David Berkheimer

January 10, 1896 – February 04, 1972

Cyperaceae

Collected Cyperaceae

Frederick W. Case

February 16, 1927 – January 12, 2011

United States

Orchidaceae

Collected Orchidaceae and identified Orchidaceae

Ottilie Diana Chermock

May 19, 1920 – November 21, 1992

United States

Hesperiidae

Collected Hesperiidae and identified Geraniaceae

Ralph Lucien Chermock

1918 – 1977

United States

Hesperiidae

Collected Hesperiidae and identified Osmundaceae

Donovan Stewart Correll

April 13, 1908 – March 28, 1983

United States

Asteraceae

Collected Asteraceae and identified Orchidaceae

Collected Poaceae and identified Poaceae

Collected Cyperaceae and identified Apiaceae

John Milton Fogg Jr.

November 08, 1898 – October 12, 1982

United States

Asteraceae

Collected Asteraceae and identified Asteraceae

Collected Poaceae and identified Poaceae

Collected Ericaceae and identified Ericaceae

John A. Gerrath

United States; Canada

Asteraceae

Collected Asteraceae and identified Asteraceae

Carl Otto Grassl

1908 – 1993

Cyperaceae

Collected Cyperaceae and identified Equisetaceae

Collected Araceae and identified Araceae

John Wesley Grear

1937 – 1981

Fabaceae

Collected Fabaceae and identified Fabaceae

Frederick Nathan Hamerstrom Jr.

July 08, 1909 – March 28, 1990

United States

Phasianidae

Collected Phasianidae

Curtis J. Hansen

United States

Asteraceae

Collected Asteraceae and identified Asteraceae

Collected Fagaceae and identified Sapotaceae

Albert Spear Hitchcock
Albert Spear Hitchcock

September 04, 1865 – December 16, 1935

United States

Poaceae

Collected Poaceae and identified Poaceae

Ellsworth Paine Killip

September 02, 1890 – November 21, 1968

United States

Asteraceae

Collected Asteraceae and identified Fabaceae

Marie-Victorin
Marie-Victorin

April 03, 1885 – July 15, 1944

Canada

Cyperaceae

Collected Cyperaceae and identified Cyperaceae

George Hill Mathewson Lawrence

1910 – June 10, 1978

United States

Collected Araliaceae and identified Plumbaginaceae

Collected Parmeliaceae and identified Parmeliaceae

Emery Clarence Leonard

June 09, 1892 – 1968

United States

Cladoniaceae

Collected Cladoniaceae and identified Acanthaceae

Bayard Henry Long

September 22, 1885 – June 09, 1969

Asteraceae

Collected Asteraceae and identified Cyperaceae

Collected Poaceae and identified Cactaceae

Collected Cyperaceae and identified Cyperaceae

Elizabeth M. Browne

January 15, 1927 – January 15, 2008

United States

Asteraceae

Collected Asteraceae and identified Asteraceae