Seaweeds of the South African South Coast

 

 

 

 

 

 

 

 

 

 

 

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Order Bryopsidales

Family Halimedaceae

Thallus divided into segments that are always calcified to some degree. Structurally, the thallus of comprises a single, multinucleate cell that forms a highly branched system of filaments running through and linking the segments. Life history diplontic, with gametangia formed on the surface of segments

Genus Halimeda Lamouroux

Thallus erect, arising from dense, felt-like rhizoidal holdfast; repeatedly branched, comprising series of calcified segments (internodes) joined by small, uncalcified, flexible nodes; branches flat or compressed. Structure of a core of medullary filaments surrounded by layers of closely adherent cortical filaments (utricles). Reproduction is by flagellate gametes that are formed in stalked gametangia on the margin or surface of segments. After release of gametes, segments lose their colour and are shed. This tropical genus comprises about 38 currently recognized species worldwide (Guiry & Guiry 2012) The account in Coppejans et al. (2005) covers most of the species recorded in South Africa, including the two found on our south coast. 

Key to species

1a. Segments usually longer than broad (wedge-shaped), separated by short stalk zones or collars	H. cuneata
1b. Segments usually broader than long, stalk zones absent; upper rim of older segments grooved	H. tuna

References Halimeda genus

Coppejans, E., Leliaert, F., Verbruggen, H. 2005. Green Algae. In De Clerck, O., J.J.Bolton, R. J. Anderson and E. Coppejans, 2005. Guide to the Seaweeds of Kwazulu-Natal. National Botanic Garden of Belgium, Brussels (Scripta Botanica Belgica), pp 40-93.

Guiry, M.D. & Guiry, G.M. 2012. AlgaeBase.

 

Cite this record as:

Anderson RJ, Stegenga H, Bolton JJ. 2016. Seaweeds of the South African South Coast.
World Wide Web electronic publication, University of Cape Town, http://southafrseaweeds.uct.ac.za; Accessed on 18 November 2024.