Morphological variability of Jania longifurca (Corallinales, Rhodophyta) in Galicia, northwestern Spain

Material of Jania J.V.Lamour. with a different morphology from the typical one attributed to J. longifurca Zanardini and J. rubens (L.) J.V.Lamour.—the only species in this habitat in Galicia—has been detected in the maerl beds of Galicia. This morphology consists on: thin intergenicula, an irregular pattern of dichotomies and secondary attachment discs that facilitate the refixation to the substrate, all of them similar to those of other southern species of Jania. Nevertheless, the integrative taxonomic study of this material and other collections from rocky habitat confirmed its identification as J. longifurca. Thereby, the atypical morphology with thin intergenicula and secondary attachment disc is dominant in samples of J. longifurca from maerl beds, while the samples from rocky environments showed the typical robust intergenicula. Moreover, molecular analysis resolved some phylogenetic affinities with samples from New Zealand, where this species is not recorded. It is concluded therefore the morphological variation related to the environment and it is evident the need of molecular studies to clarify this genus taxonomy, which is based fundamentally on morphological characters.