Intergeneric relationships within the tribe Alsineae (Caryophyllaceae) as inferred from nrDNA ITS and cpDNArps16 sequences: A step toward a phylogenetically based generic system

Abstract

The tribe Alsineae is a large monophyletic group in the family Caryophyllaceae especially found across Eurasia and the Americas, but with a center of diversity in the Mediterranean region. Several previous molecular phylogenetic studies have focused on the delimitation of genera and tribes of Caryophyllaceae, especially the subfamily Alsinoideae or the tribe Alsineae in a broader sense than now recognized. However, there are still many open questions regarding the subdivision of the tribe and genus delimitation. In the present study, we sampled 191 (148 species) and 149 (125 species) accessions of Alsineae representing almost all (Adenonema and Pseudocerastium were not available to us) recognized genera in the tribe for nuclear DNA internal transcribed spacer (ITS) and plastid marker rps16 sequences, respectively. A combined matrix of 103 species was built for taxa with both sequences available. Maximum parsimony and Bayesian inference analyses retrieved Cerastium and Stellaria (including Myosoton) as the largest monophyletic genera, while other genera were medium‐sized (10–20 spp.) or small (<10 spp.). Our expanded sampling of Pseudostellaria and its relatives suggests a broader circumscription of this genus. Major divergence in morphology, particularly of the seeds, observed in the “Protostellaria”‐clade, allows recognition of some taxonomic changes. A total of 16 genera are recognized in Alsineae including Cerastium, Dichodon, Hartmaniella, Holosteum, Lepyrodiclis, Mesostemma, Moenchia, Nubelaria, Odontostemma, Pseudostellaria, Rabelera, Schizotechium, Shivparvatia, and Stellaria, along with Adenonema and Pseudocerastium that could not be analyzed and are, therefore, kept as distinct genera. A diagnostic key to these genera, as well as notes on their relationships, distribution, and nomenclature, is provided.

Comprehensive molecular and morphological analysis of Brachystemma calycinum and Stellaria ovatifolia in the tribe Alsineae (Caryophyllaceae)

“…GenBank accession numbers nrITS trnL-F matK rps16 rcbL A. Sequences used to generate Caryophyllaceae tree (Fig. 3A) length of the petals) (1), deeply lobed (longer than 1/2 the length of the petals) (2); (b) the number of seeds in a capsule is 1-3 (0), 4-6 (1), more than 6 (2) Arabi et al 2022).…”

“…was proposed based on morphological studies (Pusalkar and Srivastava 2016). The molecular studies also indicated that Stellaria monosperma was far from the core Stellaria and nested within Schizotechium (Greenberg and Donoghue 2011;Sharples and Tripp 2019;Arabi et al 2022). Although Stellaria ovatifolia was hypothesized to be part of Schizotechium (Pusalkar and Srivastava 2016), it has never been sampled and has at times been placed in Brachystemma, Schizotechium, or Stellaria, and its phylogenetic position is still pending.…”

Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae)

“…TreeGraph 2.15.0-887 beta (Stöver & Müller 2010) was used to visualize and annotate the trees based on the Bayesian majority rule consensus, and depicting confidence values for nodes from all three tree inference methods. Scleranthus annuus L. was selected to root the trees to a relatively distant taxon outside the Alsineae and Arenarieae tribes as its putative sister (Arabi & al. 2022).…”

“…The genus Plettkea , which was not sampled by Arabi & al. (2022), is a further Andean taxon of the Alsineae that forms small cushions. However, Sharples & Tripp (2019) had already included one of its members, Plettkea tetrasticha Mattf., in their RAD analysis of the genus Stellaria along with nine South American species of Stellaria (from the ‘Petiolares’ clade), and depicted it nested within Stellaria .…”

“…Based on this first set of trnL-F and ITS sequence data, all members of the genera Plettkea and Pycnophyllopsis along with a number of taxa currently classified as Arenaria and further specimens that could not be identified using the available Floras, were recovered as part of a strongly deviant clade including the members of core Stellaria sensu Sharples & Tripp (2019) and Arabi & al. (2022).…”