Polygonella Michaux. Subfamily: Polygonoideae. Tribe: Polygoneae.
A genus of about 12-15 species, herbs and shrubs, of se. and sc. North America. Based on morphology, Ronse Decraene, Hong, & Smets (2004) suggested that Polygonella should be merged into Polygonum, as part of section Duravia; Schuster, Reveal, & Kron (2011) developed molecular evidence of the close relationship of Polygonella to the Duravia group of Polygonum and transferred the species into Polygonum. It now seems best to me to pursue an alternative course, of recognizing the very distinctive clades as separate genera – in our area, Polygonum s.s., Polygonella, and Duravia.
Ref: Freeman (2005e) In Flora of North America Editorial Committee (2005); Horton (1961); Nesom & Bates (1984); Ronse Decraene, Hong, & Smets (2004) Brandbyge in Kubitzki, Rohwer, & Bittrich (1993); Schuster et al. (2015); Schuster, Reveal, & Kron (2011); Wunderlin (1981). Show full citations.