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Order Ceramiales

Family Ceramiaceae

Pterothamnion Nägeli

Thallus erect, filamentous, (generally) ecorticate, with main axis of relatively large cells giving rise to determinate laterals and lateral axes of indeterminate growth. Each axial cell bearing two opposite branches, or with one or two additional branches in a whorl. Branches simple or re-branched up to the fourth order. Gland cells may be present. For a detailed description, see Athanasiadis & Kraft (1994). Worldwide, 28 species are currently recognized (Guiry & Guiry 2015). We tentatively recognize two species on the south coast, but the genus is rare here and we have few specimens. 

Note: the genus Pterothamnion now includes the former genera Platythamnion and Glandothamnus (see Athanasiadis & Kraft 1994). The species of Platythamnion that we had recorded on our west coast (Stegenga et al. 1997) and south coast are therefore now placed in Pterothamnion.

Key to the species

1a. The (proximal) cells of the whorl branchlets each with one ramulus

Pterothamnion sp.

1b. The (proximal) cells of the whorl branchlets each with two ramuli

Pterothamnion recurvatum

 

References Pterothamnion

Athanasiadis, A. & Kraft, G.T. 1994. Description of Pterothamnion squarrulosum (Harvey) comb. nov. from south-eastern Australia and southern New Zealand, with a taxonomic re-assessment of the genera Pterothamnion, Platythamnion and Glandothamnus (Ceramiaceae, Rhodophyta). European Journal of Phycology 29: 119-133, 27 figs, 1 table.

M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2015. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 07 December 2015.

Stegenga, H., Bolton, J.J. & R. J. Anderson. 1997. Seaweeds of the South African west coast. Contributions from the Bolus Herbarium 18: 655 pp.

 

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 24 September 2018.