Molecular systematics of <i>Cuscuta</i> subgenus <i>Monogynella</i> (Convolvulaceae) based on plastid and nuclear sequences

Abstract Cuscuta (dodders) consists of ~200 species circumscribed into four subgenera ( C. subg. Cuscuta , subg. Grammica , subg. Monogynella , subg. Pachystigma ) and is the only parasitic genus in Convolvulaceae (the morning‐glory family). This genus shows a significant diversity in plastid functionality and represents a rare mixotrophic system within parasitic plants, where different trophic modes can be found at a lower phylogenetic level. Cuscuta subg. Monogynella contains chlorophyllous hemiparasitic species distributed primarily across Eurasia, with Central Asia as its center of diversity. Apart from a few placeholders in broad‐scale phylogenies, this group has not been extensively sampled and studied taxonomically, morphologically, or geographically. Our paper presents the first in‐depth phylogeny for C. subg. Monogynella based on plastid trnL‐F and nuclear ITS sequence regions. Our wide taxon sampling included 12 out of the 15 presently recognized species, with specimens from across their geographic distribution. Our analyses show highly congruent trees, forming similar clades using both plastid and nuclear markers, with no indication of hybridization. Most of the species, represented by multiple individuals from various geographic regions, have been found reciprocally monophyletic or paraphyletic. One individual from south‐west China formed its own separate lineage, with substantial branch length subtending it, and given its distinct geographic distribution, likely belongs to a new species.