Resolving the identity of Jania crassa (Corallinales, Rhodophyta)

ABSTRACTDNA sequences obtained from the isolectotype of Jania crassa, collected from Dusky Sound, Fiordland, New Zealand, have revealed the identity of this poorly understood taxon, and enabled comparison with modern material. The name Jania crassa has been previously widely applied in New Zealand and Australia. Data presented here show that Jania crassa differs from other species within the New Zealand region: of the eight species of Jania currently recognized, three are dichotomously branched, and two of these are known from southern New Zealand. Jania crassa can be distinguished from the smaller and epiphytic species of Jania in southern New Zealand, J. sphaeroramosa, on the basis of size and growth habit. Jania crassa appears to be an infrequently collected, possibly endemic species of southern New Zealand, with only one recent collection confirmed. Further collections and sequence data are needed to better understand the distribution of this species, particularly in neighbouring regions.KEYWORDS: Coralline algaeCorallinophycidaeFiordlandNew Zealandtype specimen ACKNOWLEDGEMENTSWe thank the many people who have assisted with field work and contributed to collections of coralline algae from New Zealand, particularly Kate Neill, Tracy Farr, Roberta D’Archino, and Chris Hepburn, and the team at the University of Otago. We are very grateful to the skipper and crew of the RV Polaris for field work in Fiordland and Rakiura, and for field assistance from Ngāi Tahu (Ngāi Tahu Te Tiaki Mahinga Kai). We very much appreciate the assistance of herbarium staff at Te Papa Tongarewa Museum of New Zealand; and Erika Mackay and Kate Neill (NIWA) for preparation of plates.DISCLOSURE STATEMENTNo potential conflict of interest was reported by the authors.Supplementary InformationSupplemental data for this article can be accessed online at https://doi.org/10.1080/00318884.2023.2253694Additional informationFundingThis work was supported by NIWA SSIF funding.