Evidence for the reinstatement of Kallymeniopsis and the merger of the family Crossocarpaceae within the family Kallymeniaceae (Rhodophyta)

Abstract We present a three-gene phylogeny, based on nuclear (short fragment of large subunit ribosomal RNA gene, 1150 base pairs), chloroplast (ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit) and mitochondrial (5′ region of the cytochrome oxidase subunit 1) genes, to determine the position of three species, Kallymeniopsis verrucosa, Beringia castanea and Crossocarpus lamuticus in the Gigartinales. These species were placed by Perestenko in the family Crossocarpaceae, a proposal that was not supported by most phycologists. The goal of this project was to resolve the taxonomic position of these three species and answer the question: Is the Crossocarpaceae a separate family? The concatenated multi-gene phylogeny and the individual gene trees show that these algae nest deeply within the family Kallymeniaceae; K. verrucosa and C. lamuticus are most closely related to species referred currently to the genus Erythrophyllum, whereas B. castanea is sister to the recently established Commanderella ruprechtiana. Taking into account the data on morphology, vegetative and reproductive anatomy of different species, we propose to revive the genus Kallymeniopsis with three species and to retain Crossocarpus as a separate genus. Beringia is a separate monotypic genus.