The complete chloroplast genome of <i>Origanum vulgare</i> L. (Lamiaceae) from AL-Madinah, Saudi Arabia, and its phylogenetic relationship

The genus <i>Origanum</i> is taxonomically complex and often considered an underutilized group despite its economic and medicinal significance. <i>Origanum vulgare</i> L., the most variable species within the genus, is widely utilized as a culinary spice and medicinal herb, exhibiting considerable morphological diversity across its six recognized subspecies. In this study, we assembled and annotated the complete chloroplast (cp) genome of a wilt-resistant Saudi Arabian accession of <i>O. vulgare</i>. The cp genome measures 151,826 bp in length and displays the typical circular quadripartite structure, consisting of a large single copy (LSC) region (83,014 bp), a small single copy (SSC) region (17,620 bp), and a pair of inverted repeats (IRs) (25,596 bp each). It contains 129 genes, including 85 protein-coding genes, 36 transfer RNA genes, and 8 ribosomal RNA genes. Notably, the Saudi accession possesses a duplicated <i>rps19</i> gene, and its cp genome length differs from that of other <i>O. vulgare</i> accessions. Phylogenetic analysis clustered all <i>O. vulgare</i> accessions into a single well-supported clade, revealing considerable genetic divergence among populations. Furthermore, the genus <i>Origanum</i> was strongly supported as sister to <i>Thymus</i>. This study provides a valuable chloroplast genome resource for evolutionary, taxonomic, and conservation studies in <i>O. vulgare</i> and related taxa within the Lamiaceae.