''Polygonum serotinum'', commonly called southern jointweed or American jointweed, is a species of flowering plant in the knotweed family. It is native to

Southeastern United States The Southeastern United States, also referred to as the American Southeast or simply the Southeast, is a geographical region of the United States. It is located broadly on the eastern portion of the southern United States and the southern por ...

extending in scattered locations west to

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe , LargestCity = Albuquerque , LargestMetro = Tiguex , OfficialLang = None , Languages = English, Spanish ( New Mexican), Navajo, Ker ...

. Its preferred habitat is dry, sandy areas. ''Polygonum serotinum'' was first described in 1820 by

Constantine Samuel Rafinesque Constantine Samuel Rafinesque-Schmaltz (; October 22, 1783September 18, 1840) was a French 19th-century polymath born near Constantinople in the Ottoman Empire and self-educated in France. He traveled as a young man in the United States, ultimat ...

. It was at one time placed in the genus ''Polygonella'' (under the name ''Polygonella ''), but in 2015, following a series of

molecular phylogenetic Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

studies, this genus was subsumed into ''

Polygonum ''Polygonum'' is a genus of about 130 species of flowering plant in the buckwheat and knotweed family Polygonaceae. Common names include knotweed and knotgrass (though the common names may refer more broadly to plants from Polygonaceae). In the ...

''.

References

serotinum Flora of the Southeastern United States Flora of New Mexico Plants described in 1820 Taxa named by Constantine Samuel Rafinesque Flora without expected TNC conservation status {{Polygonaceae-stub