Resolving the identity of Jania crassa (Corallinales, Rhodophyta).

DNA 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. [ABSTRACT FROM AUTHOR]