Assessment of the order Rhodymeniales (Rhodophyta) from British Columbia using an integrative taxonomic approach reveals overlooked and cryptic species diversity

Abstract

Molecular-assisted alpha taxonomy using COI-5P and rbcL-3P was employed to reassess species diversity for the Rhodymeniales (Rhodophyta) in British Columbia. A total of 563 collections from British Columbia were resolved as 16 genetic species groups, whereas 13 were previously reported. Collections attributed to Botryocladia pseudodichotoma from British Columbia were resolved as distinct from collections of that species from California (type locality) and were assigned to Botryocladia hawkesii sp. nov. DNA sequence data also resolved an additional species of Fryeella. Although two species of Gloiocladia were recognized, genetic analyses resolved three: G. fryeana, G. laciniata, and Gloiocladia vigneaultii sp. nov. Data also resolved Gloiocladia media comb. nov. from California. For the genus Rhodymenia, where two species were expected, DNA sequence data resolved four. Both R. californica and R. pacifica were confirmed in British Columbia, whereas some collections field-identified as R. californica were genetically distinct and assigned to the novel species, Rhodymenia bamfieldensis sp. nov. Some collections initially identified as R. pacifica were assigned to the resurrected species R. rhizoides. Anatomical development for the monospecific genus Minium was also reassessed owing to that taxon’s assignment to the Fryeellaceae. Our investigation clarified the number of rhodymenialean species in British Columbia and resolved taxonomic and distributional uncertainties associated with some of these taxa.