Pollen morphology and taxonomy of Atraphaxis (Polygoneae, Polygonaceae)

Flower, seed, and fruit development in three Tunisian species of Polygonum: Implications for their taxonomy and evolution of distyly in Polygonaceae

“…They are all tricolporate showing variation only in shape and size. In agreement with previous findings in other Polygonum species showing that this genus has prolate to spheroidal pollen and the aperture is mostly tricolporate, rarely panto-hexacolporate with several types of exine ornamentation [45,46]. The largest pollen size was observed in P. equisetiforme, while the smallest one in P. maritimum.…”

A broadly sampled 3-loci plastid phylogeny of Atraphaxis (Polygoneae, Polygonoideae, Polygonaceae) reveals new taxa: I. Atraphaxis kamelinii spec. nov. from Mongolia

“…For example, based on the results of phylogenetic analyses, several species of Polygonum, with equal-sized perianth segments but the stem lignification and habit typical of Atraphaxis, have been transferred to Atraphaxis (Yurtseva et al 2010, Schuster at al. 2011b, Yurtseva et al 2012, and these results were confirmed by observations of pollen morphology (Yurtseva et al 2014), life history, and other morphological chracteristics (Yurtseva et al 2016). The latest yet preliminary circumscription of Atraphaxis (Schuster et al 2011a, b;Tavakkoli et al 2015;Yurtseva et al 2016) The phylogenetic analyses of Atraphaxis (21 species) (Zhang et al 2014) argue for the division of the genus into two major clades, with A. teretifolia (monotypic A. section Physopyrum) nested in one subclade, and A. section Atraphaxis, which includes the generic type A. spinosa, as part of the second subclade.…”

“…This caespitose perennial herb, with sausage-shaped succulent leaves and axillary cymes of flowers at annual shoots, is a local endemic of Central Iran (Tehran region) (Mozaffarian 1988(Mozaffarian , 2012. It is morphologically quite different from other species of Atraphaxis but has the striate-perforate ornamentation of sporoderm (Tavakkoli et al 2015), peculiar to Atraphaxis (Yurtseva et al 2014). In ITS-based phylogeny it is however nested in Polygonum sect.…”

“…& Spach, A. billardierei, A. canescens Bunge, A. compacta Ledeb., A. decipiens Jaub. & Spach, A. frutescens, A. karataviensis Pavlov & Lipsh., A. muschketowi Krasn., A. replicata, A. rodinii Botsch., A. spinosa, A. teretifolia, A. virgata (see more in Yurtseva et al 2014).…”

“…Our phylogenetic and palynological studies placed a morphologically distinctive endemic from Pamir, Polygonum ovczinnikovii Czukav. (Czukavina 1962), into Atraphaxis (Yurtseva et al 2012(Yurtseva et al , 2014, which was subsequently recognized as A. ovczinnikovii (Czukav.) O.V.Yurtseva.…”