Molecular phylogenetics, seed morphometrics, chromosome number evolution and systematics of European Elatine L. (Elatinaceae) species

• Published in: PeerJ (San Francisco, CA) Vol. 4; p. e2800
• Main Authors: Sramkó, Gábor, Molnár V, Attila, Tóth, János Pál, Laczkó, Levente, Kalinka, Anna, Horváth, Orsolya, Skuza, Lidia, Lukács, Balázs András, Popiela, Agnieszka
• Format: Journal Article
• Language: English
• Published: United States PeerJ. Ltd 21.12.2016; PeerJ, Inc; PeerJ Inc
• Subjects: Biology; Botany; Character evolution; Chromosome number; Elatinaceae; Elatine; Elatine californica; Elatine ecuadoriensis; Elatine triandra; Elatinella; Evolution; Flowers & plants; Genetic variability; Genomes; Hydropipera; Macropodae; Malpighiales; Morphology; Morphometry; Museums; Phylogenetics; Phylogeny; Plant Science; Plant sciences; Seeds; Species; Species delimitation; Taxonomy; Waterwort; Poland; Hungary; United States > US; North America; Europe; Spain; Elatinella; Incongruence; Character evolution; Hydropipera; Macropodae; Hybridization; Species delimitation; Waterwort
• ISSN: 2167-8359; 2167-8359
• DOI: 10.7717/peerj.2800

The genus contains 25 species, all of which are small, herbaceous annuals distributed in ephemeral waters on both hemispheres. However, due to a high degree of morphological variability (as a consequence of their amphibious life-style), the taxonomy of this genus remains controversial. Thus, to fill this gap in knowledge, we present a detailed molecular phylogenetic study of this genus based on nuclear (rITS) and plastid ( , , ) sequences using 27 samples from 13 species. On the basis of this phylogenetic analysis, we provide a solid phylogenetic background for the modern taxonomy of the European members of the genus. Traditionally accepted sections of this tree (i.e.,  and ) were found to be monophyletic; only -found to be a basal member of the genus-has to be excluded from the latter lineage to achieve monophyly. A number of taxonomic conclusions can also be drawn: , a high-ploid species, is most likely a stabilised hybrid between the main sections; merits full species status based on both molecular and morphological evidence; is a more widespread and genetically diverse species with two main lineages; and the presence of the Asian in the European flora is questionable. The main lineages recovered in this analysis are also supported by a number of synapomorphic morphological characters as well as uniform chromosome counts. Based on all the evidence presented here, two new subsections within are described: subsection consisting of the temperate species of the section, and subsection including the Mediterranean species of the section.