Current status of freshwater red algal diversity (Rhodophyta) of the African continent including description of new taxa (Batrachospermales)

ABSTRACT

Freshwater red algae have been collected on the African continent since the early 1800s. However, the collections have been sparse and geographically restricted. The present study sought to bring together information from the literature, herbarium specimens, and newly collected specimens to provide an updated assessment of the freshwater red algal diversity of the African continent with a focus on the species-rich Batrachospermales. DNA sequence data and morphological observations were conducted for recently collected specimens. From these analyses, four new taxa are proposed: Kumanoa bouwmanii, Sheathia murpheyi, Sirodotia kennedyi, and the form taxon ‘Chantransia azurea’. DNA sequence data had been previously published for Kumanoa iriomotensis, Sirodotia aff. huillensis, and S. suecica. With this study, we have added sequence data for Torularia atra as well as a second location for S. suecica. In total, there are eight taxa with sequence data, of which five appear to be endemic. From our assessment of literature reports and herbarium specimens, we conclude that Kumanoa, Sirodotia, and Torularia have often been collected and are relatively geographically widespread with two or more species present. In addition, Montagnia, Nothocladus, Paralemanea, Sheathia, and Visia as well as Batrachospermum section Gonimopropagulum are represented in the flora. We estimate that 14 to 19 batrachospermalean taxa can be recognised for the African flora, and that with more study, that number could easily double or triple based on the diversity known from other well-studied continents.

KEYWORDS:

• Africa
• Batrachospermales
• Biogeography
• COI-5P
• Freshwater red algae
• Molecular systematics
• Morphology
• rbcL gene
• Rhodophyta
• Taxonomy

ACKNOWLEDGEMENTS

MLV gratefully acknowledges the colleagues at PC for hosting her and allowing access to collections. This research was facilitated by specimen loans from FH and MICH. Mike Guiry and Mike Wynne are thanked for their help with nomenclature and determining validity of older species epithets. Some of the research was conducted while MLV was an invited professor at PC and a Fulbright Scholar in Brazil.

SUPPLEMENTARY DATA

Supplemental data for this article can be accessed on the publisher’s website.

Additional information

Funding

Funding for this research was provided by grants NSF DEB 0235676, 0936855, and 1655230 to MLV. The European Commission/African, Caribbean and Pacific Group of States (EC/ACP) Science & Technology Programme (AFS/2009/219013) funded the SAFRASS program and sample collection in Zambia by JCT. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of NSF.