Taxonomy of Polygonoideae (Polygonaceae): A new tribal classification

Abstract

The subfamily Polygonoideae has a world‐wide distribution and is an important component of many countries’ floras. In this study we present the most comprehensive sampling available to date, including data from three chloroplast genes (matK, ndhF, rbcL) for 82 species in Polygonaceae (54 from Polygonoideae). Based on our results, we propose a new taxonomic classification for Polygonoideae that includes five well‐supported tribes: Calligoneae, Fagopyreae, Persicarieae, Polygoneae, and Rumiceae. Overall, the results from molecular data represent significant progress in understanding the evolutionary relationships of major groups within the family. This classification also provides an assessment of diagnostic morphological characters for the tribes. The present work will promote reevaluation of morphological characters within this diverse group, especially synapomorphies for Polygonoideae, and for tribes with a particularly complex history such as Fagopyreae, Persicarieae, and Polygoneae. A new combination, Fagopyrum tibeticum, is proposed.

Age Estimates for the Buckwheat Family Polygonaceae Based on Sequence Data Calibrated by Fossils and with a Focus on the Amphi-Pacific Muehlenbeckia

“…1) of one nr (ITS) and three cp ( mat K, ndh F and trn L- trn F) markers for the most part show the same results for the evolutionary relationships among and within all genera included when compared to the ML and Maximum Parsimony analyses of other studies (e.g., [1], [22], [23], [51], [52]). Since the evolutionary relationships among clades and the placement of genera within Polygonaceae are congruent across these studies, these results will not be reiterated here and only differences are discussed briefly.…”

“…with approximately 1,200 species [1] is morphologically diverse and growth forms include trees, shrubs, vines, lianas and herbs. Polygonaceae are found in a wide range of habitats from the Arctic to the tropics, from montane to lowland regions, and from arid to aquatic situations.…”

Tertiary montane origin of the Central Asian flora, evidence inferred from cpDNA sequences of Atraphaxis (Polygonaceae)

“…Systematically, Atraphaxis , Calligonum , and Pteropyrum formerly constituted Tribe Atraphaxideae (Dammer ), or subtribe Atraphaxidinae (Jaretzky ; Hong ), and a Tibetan genus, Parapteropyrum (Li ; Bao and Li ), was a subsequent addition to the group. However, this tribe, including these four genera, was shown to be non‐monophyletic in terms of a recent molecular phylogeny (Lamb‐Frye and Kron ; Sanchez and Kron , , ; Tavakkoli et al ; Sanchez et al , ; Sun and Zhang ). As a result, Atraphaxis is now placed in tribe Polygoneae, while Calligonum and Pteropyrum are located in tribe Calligoneae, distant from Atraphaxis (Sanchez et al , 2011b; Tavakkoli et al ; Sun and Zhang ), and Parapteropyrum is included in Fagopyreae (Sanchez et al 2011a, 2011b).…”

Reproductive biology and variation of nuclear ribosomal ITS and ETS sequences in the Calligonum mongolicum complex (Polygonaceae)

“…Molecular analyses of both nrDNA ITS and some cpDNA sequences ( trn L-F, mat K, atp B- rbc L, psb A- trn H, psb K- psb L and rbc L) have not resolved relationships amongst species of Calligonum (Sanchez et al 2011, Sun and Zhang 2012, Li et al 2014). Our study showed that Calligonum ebinuricum possesses highly distinct nrITS sequences (Figures 3 & 4); yet the ITS and ETS sequences of the Calligonum mongolicum complex generated a topology with the species of the complex highly intermixed with each other in the tree.…”

“…Medusae . The taxonomic relationships of the genus have been tested by the applications of several molecular techniques, such as the RAPD markers (Ren et al 2002) and other chloroplast DNA markers ( trn L-F, mat K, atp B- rbc L, psb A- trn H, psb K- psb l and rbc L) (Tavakkoli et al 2010; Sanchez et al 2011; Abdurahman and Sabirhazi 2012; Sun and Zhang 2012; Li et al 2014), but the markers employed so far have been inefficient for resolving the taxonomic problems in Calligonum . It was expected that reproductive biology and faster-evolving nuclear DNA sequences (Sang 2002; Zimmer and Wen 2012) might shed some light on the taxonomy of the genus.…”