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Laurencia complanata

This guide covers the seaweeds (marine macro-algae, excluding the crustose corallines) of approximately 1000 km of coastline, from Cape Agulhas to the Umtamvuna River (the border between the Eastern Cape and KwaZulu-Natal provinces). This is largely a discrete biogeographic area and includes the entire Agulhas Marine Province as well as some of the overlap zone with the KwaZulu-Natal flora. However, the seaweeds of the south coast have not been comprehensively documented, although there is some overlap with existing publications for the west coast (Stegenga et al. 1997, Seaweeds of the South African West Coast. Contributions from the Bolus Herbarium 18: 655 pp.) and Kwazulu-Natal (DeClerck et al. 2005, Guide to the Seaweeds of KwaZulu-Natal. Scripta Botanica Belgica 33: 294 pp.).To make this account as complete as possible, we include the species that are already covered in those books.

Users of this guide are reminded that continuing studies will lead to changes in systematics and the names of some seaweeds, but that these can be checked on the excellent website

We have tried to make the guide as complete as possible, to the extent of including taxa that do not fit any current descriptions (e.g. as sp. 1, sp. 2,). To have studied these further would have prevented us from ever finishing, but our information on these taxa should nevertheless be useful to other phycologists (those who study algae).

Descriptions are based on existing literature and examinations of specimens and microscope sections. Illustrations are our own photographs of specimens or microscope slides, and where appropriate, scans of Herre Stegenga’s excellent drawings from “Seaweeds of the South African West Coast”. In a few cases we re-drew illustrations from other publications.

Note on format and structure

This guide is in a number of sections. The main (systematic) sections are in the customary order of Green, Brown and Red Seaweeds. Within each of these, genera are arranged by Order and Family, but no descriptions of these higher taxa are provided. Genera are briefly described when they contain two or more species, with a key to the species. Full descriptions and illustrations are then given for each species. Taxonomic terms are explained in the Glossary, and references are included under each species. 


We are deeply indebted to Professor Michael Guiry and his colleagues who built and maintain the incomparable algal website – without it we would never have attempted this guide.

Our heartfelt thanks to Chris Boothroyd and Derek Kemp for their enthusiastic and invaluable technical help throughout the project.

We thank our colleagues and post-graduate students whose knowledge has been of enormous help, especially, Olivier DeClerck, Frederik Leliaert, Heroen Verbruggen and Eric Coppejans (Ghent University, Belgium), Enrico Tronchin (UCT) and others. We thank Lydiane Mattio for contributing the section on Sargassum.

This work was funded from several sources over many years. FRD/NRF Post-doctoral bursaries sustained Herre Stegenga at Rhodes University and at UCT when he made many collections of specimens and microscope slides. DAFF (Department of Agriculture, Forestry and Fisheries) supported the participation of Anderson, Kemp and Boothroyd. SANPAD (South Africa Netherlands research Programme on Alternative Development) grants allowed us to train students and improve our collections from the south coast between 2001 and 2004. Various grants from NRF, UCT and DAFF all contributed through various projects. Most importantly, NRF funding of the SeaKeys Programme supported the development of this website. SANPARKS allowed us access to marine parks where important records were found. Finally, we thank the curators of the BOL and GRA herbaria for access to collections.

The Team

Rob Anderson (on left) and Herre Stegenga,
Amsterdam, 2014.

John Bolton, Goukou Estuary.

Derek Kemp, Dwesa.

Chris Boothroyd, Dwesa.

Citing this publication:

Anderson RJ, Stegenga H, Bolton JJ. 2016. Seaweeds of the South African South Coast.
World Wide Web electronic publication, University of Cape Town,; Accessed on 21 January 2018