Insights into the rare Mediterranean endemic Kallymenia spathulata: DNA phylogenies resolve this species as Halymeniaceae (Halymeniales) rather than Kallymeniaceae (Gigartinales), with the proposal of Felicinia spathulata comb. nov.

The rare endemic Mediterranean alga Kallymenia spathulata was collected at Nice and Saint Raphael in June 2013 during a survey conducted along the French Mediterranean coast between Menton and Toulon (French Riviera). DNA barcode sequences (COI-5P) generated from the five collected specimens were identical and allied with Felicinia marginata, another Mediterranean endemic that is classified within the Halymeniaceae (Halymeniales) whereas the genus Kallymenia is representative of the Kallymeniaceae (Gigartinales). We further confirmed the alliance of K. spathulata with Felicinia marginata by conducting phylogenetic analyses inferred by combined genes including Cox1, rbcL and LSU. Unfortunately, none of the specimens were fertile, precluding emending the description of the reproductive anatomy of this species. In light of our phylogenies, we propose the novel combination Felicinia spathulata. The genus Felicinia now comprises two species, both endemic to the Mediterranean Sea.