Long-distance dispersal explains the bipolar disjunction in .

Premise Of The Study: The sedge d'Urv presents a bipolar distribution. To clarify the origin of its distribution, we consider the four main hypotheses: long-distance dispersal (either by mountain hopping or by direct dispersal), vicariance, parallel evolution, and human introduction.

Methods: Phylogenetic, phylogeographic, and divergence time estimation analyses were carried out based on two nuclear ribosomal (ETS and ITS) regions, one nuclear single copy gene (CATP), and three plastid DNA regions (16 and 5'K introns, and AH spacer), using Bayesian inference, maximum likelihood, and statistical parsimony. Bioclimatic data were used to characterize the climatic niche of . .

Key Results: constitutes a paraphyletic species, dating back to the Pleistocene (0.62 Mya, 95% highest posterior density: 0.29-1.00 Mya). This species displays strong genetic structure between hemispheres, with two different lineages in the Southern Hemisphere and limited genetic differentiation in Northern Hemisphere populations. Also, populations from the Southern Hemisphere show a narrower climatic niche with regards to the Northern Hemisphere populations.

Conclusions: reached its bipolar distribution by long-distance dispersal, although it was not possible to determine whether it was caused by mountain hopping or by direct dispersal. While there is some support that might have colonized the Northern Hemisphere by south-to-north transhemisphere dispersal during the Pleistocene, unlike the southwards dispersal pattern inferred for other bipolar L. species, we cannot entirely rule out north-to-south dispersion.