Systematics and phylogeny of Arenaria s.str. (Caryophyllaceae) with special focus on Latin American species

VON MERING, SABINE; MONTESINOS-TUBÉE, DANIEL; ACOSTA, JUAN MANUEL; BORSCH, THOMAS; MENESES, ROSA

Congreso; Caryophyllales 2018; 2018

The circumscription of the genus Arenaria (sandworts) has long been debated and changedseveral times in the past. Recent molecular phylogenetic studies have shown that the genusin its old and wider circumscription was polyphyletic resulting in the segregation of severalformer subgenera as distinct genera (e.g. Eremogone, Odontostemma, Shivparvatia). Arenarias.str. comprises about 100-135 species of small annual or perennial herbs distributed mostlyin temperate and colder regions of the Northern hemisphere (Holarctic) but extending tosouthern South America. Many Arenaria species are found in dry and sandy habitats or onhigh mountains. While many Eurasian Arenaria species were included in a recent study bySadeghian et al. (2015), little attention has been paid to the Central and South Americanspecies of the subgenera Leiosperma and Dicranilla. This group also includes a number ofspecialized cushion plants adapted to high altitude habitats. Since species numbers andlimits are uncertain, a broad sampling is aimed for, including accessions covering geographicdistribution and morphological variability. Sequence data for three molecular markers(matK-trnK, trnL-trnF, and ITS) have been generated so far and the data set will be expandedto include the regions matK-trnK-psbA, trnL-trnF, and rpl16 as standard chloroplast marker.Preliminary results of our phylogenetic analyses show that a Neotropical clade includingall the Andean Arenaria taxa is emerging, and indicating that subgenera Leiosperma andDicranilla are probably not natural groups in the current circumscription. Within this projectthe EDIT Platform for Cybertaxonomy is used as a tool to assemble a dynamic and integrativemonography of Arenaria and relatives presenting the status quo of our knowledge aboutthe genus.