The two species placed in the genus were for many years sunk into a broadly defined genus
Cynanchum. In 2005, on the basis of both
molecular phylogenetic and morphological evidence, it was proposed that they should be placed in a separate genus. Determining the correct name to be used for this genus involves a complex taxonomic history. The genus was first described in 1817 by Elliott using the name
Lyonia. However, this name had already been published in 1808 by
Constantine Samuel Rafinesque for a genus in the family
Polygonaceae, so Elliott's name is an
illegitimate later
homonym. In 1818, Rafinesque published a
replacement name,
Macbridea. This too has been treated as an illegitimate later homonym, as
Thomas Nuttall had published
Macbridea in the same year for a genus in the family
Lamiaceae, ascribing the name to Elliott. In 1828,
Ludwig Reichenbach published
Seutera as a replacement name for Elliott's
Lyonia, unaware of Rafinesque's
Macbridea. In 1889,
Sereno Watson published the name
Pattalias. It is now considered that Rafinesque may have published
Macbridea a few weeks before Nuttall, so
Seutera is superfluous. (It could also be confused with
Sutera.) A proposal to conserve
Seutera was rejected. As
Macbridea has been conserved against
Macbridea , the remaining legitimate name is Watson's
Pattalias.
Species Two species are accepted: •
Pattalias palmeri S. Watson - Baja California Sur •
Pattalias palustris (Pursh) Fishbein - Cuba, southeastern United States, Veracruz, Yucatán Peninsula ==References==