Seaweeds of the South African South Coast
Order Ceramiales
Family Ceramiaceae
Antithamnionella Lyle
Plants filamentous, uncorticated, usually partly prostrate, partly erect: thalli differentiated into long indeterminate axes and short determinate whorl-branches. Whorl-branches occurring in numbers from 1 to 6 per segment, the number usually variable within the species. Gland cells more or less abundant, found on unmodified cells of the whorl-branches. Tetrasporangia formed on proximal cells of the whorl-branches, sessile or pedicellate, tetrahedrally divided. Spermatangial heads small, shortly cylindrical, developing on proximal cells of whorl-branches. Procarp formed on the basal cell of a reduced, two-celled whorl-branch, closely below the apex of erect indeterminate axes; main axes discontinuing growth with the production of a carposporophyte. Carposporophytes with a varying number of gonimolobes, without an involucre. Of the 25 currently recognised species (Guiry & Guiry 2015), five are recorded on the south coast.
Key to the species
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1a. Plants with two (more rarely three) laterals per cell |
Antithamnionella spirographidis |
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1b. Plants regularly with three or more laterals per cell |
2 |
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2a. Determinate laterals within one whorl strongly dissimilar |
Antithamnionella tormentosa |
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2b. Determinate laterals in a whorl of about similar development. |
3 |
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3a. Determinate laterals usually unbranched, or with one (to three) laterals |
4 |
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3b. Determinate laterals usually with alternating laterals |
Antithamnionella sp. |
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4a. Determinate laterals usually with prominent, almost globose gland cells on the second cell |
Antithamnionella verticillata |
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4b. Determinate laterals with flattened gland cells higher up |
Antithamnionella ternifolia |
References Antithamnionella
Guiry, M.D. & Guiry, G.M. 2015. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 16 September 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 19 December 2024.