Deep sequencing of the epitype specimen of Synarthrophyton patena (Hooker f. & Harvey) RATownsend (Hapalidiales, Rhodophyta) confirms the correct application of this name

Synarthrophyton patena (Hooker f. & Harvey) R.A.Townsend is a discoid marine coralline red alga distributed in the southwestern Pacific Ocean (type locality: southeast North Island, New Zealand). It is the generitype of Synarthrophyton R.A.Townsend, a genus of taxonomic debate. High-throughput sequencing was performed on the herein designated epitype specimen of S. patena to characterize its genetic markers and organellar genome structure. The complete plastid genome of S. patena is 181,685 bp in length and contains 232 genes. A partial mitogenome was assembled amounting to 25,779 bp and encodes 46 genes. Both genomes show a high level of gene synteny to the organellar genomes of S. chejuense. DNA markers rbcL, psbA, and cox1 are identical or very similar to sequences deposited in GenBank and analyzed here under the same name from Australia (including Tasmania) and New Zealand. A combined phylogenetic analysis of S. patena using rbcL and psbA gene sequences fully resolved it in a clade with other S. patena, Synarthrophyton spp., and unidentified Hapalidiales. These data confirm the accurate application of the binomial S. patena, stabilize the use of the generitype, and contribute to future congeneric evolutionary and taxonomic studies in the Hapalidiaceae.