Phylogeny of Polygoneae (Polygonaceae: Polygonoideae)

Genera included in Polygoneae such as Atraphaxis, Duma, Fallopia, Muehlenbeckia, Polygonella, Polygonum, Oxygonum , and Reynoutria are investigated using a molecular framework. Previous morphological studies had indicated that Polygonum is composed of sections Duravia, Polygonum , and Pseudomollia with the genus Polygonella included as a subsection of Polygonum sect. Duravia . One nuclear (nrITS) and three chloroplast ( matK, ndhF, trnL–trnF ) regions were analyzed with Maximum Parsimony and Maximum Likelihood methods to address evolutionary relationships within the tribe. The results show that Polygoneae is composed of three main clades: Knorringia as sister to all other taxa within Polygoneae, a clade of Reynoutria and Fallopia + Muehlenbeckia , and their sister clade of Atraphaxis, Duma , and Polygonum . The currently accepted sections within Polygonum are recovered and Polygonum sect. Duravia is sister to sections Polygonum and Pseudomollia. With Polygonella included in Polygonum , the appropriate new combinations and names are proposed. In addition, a few species of Polygonum are transferred to Atraphaxis . Oxygonum is not supported as a member of Polygoneae and its exact position awaits additional data.