Disentangling relationships among eastern Mediterranean Cymbalaria including description of a novel species from the southern Peloponnese (Greece)

Pau Carnicero,Núria Garcia-Jacas,Mercè Galbany-Casals,Theophanis Constantinidis,Llorenç Sáez

doi:10.1007/s00606-020-01730-3

Abstract

The eastern Mediterranean basin hosts a remarkably high plant diversity. Historical connections between currently isolated areas across the Aegean region and long-distance dispersal events have been invoked to explain current distribution patterns of species. According to most recent treatments, at least two Cymbalaria species occur in this area, Cymbalaria microcalyx and C. longipes. The former comprises several intraspecific taxa, treated at different ranks by different authors based on morphological data, evidencing the need of a taxonomic revision. Additionally, some populations of C. microcalyx show exclusive morphological characters that do not match any described taxon. Here, we aim to shed light on the systematics of eastern Mediterranean Cymbalaria and to propose a classification informed by various sources of evidence. We performed molecular phylogenetic analyses using ITS, 3’ETS, ndhF and rpl32-trnL sequences and estimated the ploidy level of some taxa performing relative genome size measures. Molecular data combined with morphology support the division of traditionally delimited C. microcalyx into C. acutiloba, C. microcalyx and C. minor, corresponding to well-delimited nrDNA lineages. Furthermore, we propose to combine C. microcalyx subsp. paradoxa at the species level. A group of specimens previously thought to belong to Cymbalaria microcalyx constitute a well-defined phylogenetic and morphological entity and are described here as a new species, Cymbalaria spetae. Cymbalaria longipes is non-monophyletic, but characterized by being glabrous and diploid, unlike other eastern species. The nrDNA data suggest at least two dispersals from the mainland to the Aegean Islands, potentially facilitated by marine regressions.

Highlights

The eastern Mediterranean basin comprises two major centers of biodiversity, the Balkan-Aegean area with 6500–7000 species, of which ca. 1500 are endemic, and the1 3 Vol.:(0123456789) 13 Page 2 of 19Mediterranean part of the Anatolian Peninsula with ca. 5000 species, of which 30% are endemic (Thompson 2005)
Cymbalaria Hill (Plantaginaceae) originated ca. 4 Ma in the central-eastern Mediterranean basin and rapidly diverged in three lineages (Carnicero et al 2017), which further diverged in ten species and seven subspecies according to the most recent publications (Sutton 1988; Bigazzi and Raffaelli 2000; Carnicero et al 2018, 2019)
The analyses of the nrDNA with Maximum Parsimony (MP) and Bayesian inference (BI) resulted in congruent phylogenetic tree topologies and retrieved three main lineages (Fig. 2)

Summary

Introduction

The eastern Mediterranean basin comprises two major centers of biodiversity, the Balkan-Aegean area with 6500–7000 species, of which ca. 1500 are endemic, and the1 3 Vol.:(0123456789) 13 Page 2 of 19Mediterranean part of the Anatolian Peninsula with ca. 5000 species, of which 30% are endemic (Thompson 2005). 4 Ma in the central-eastern Mediterranean basin and rapidly diverged in three lineages (Carnicero et al 2017), which further diverged in ten species and seven subspecies according to the most recent publications (Sutton 1988; Bigazzi and Raffaelli 2000; Carnicero et al 2018, 2019). It is a genus of perennial herbs distributed throughout the Mediterranean basin, most taxa are endemics of small areas.

Objectives

Results

Conclusion