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Order Ceramiales

Family Wrangeliaceae

Griffithsia C. Agardh

Plants filamentous, ecorticate, in general subdichotomously branched. Thalli consisting of very large ellipsoid, clavate or cylindrical cells that are multinucleate. Tetrasporangia in whorls on intercalary cells, with or without a ring of involucral cells. Spermatangial heads whorled like the tetrasporangia (rarely capping an apical cell), with or without involucral cells. Female fertile filament three-celled, developing on an apical cell, but displaced by vegetative cells and moved into a lateral position. Carposporophytes with a central fusion cell and few to several gonimolobes, surrounded by involucral cells or two-celled involucral branches.

Thirty-nine species are currently recognized (Guiry & Guiry 2015). We recognize three on the south coast, including one that is apparently undescribed.

Griffithsia – key to the species

1a. Filaments strongly moniliform. Carposporophyte with five involucral filaments from the basal cell of
the female fertile filament

Griffithsia sp.

1b. Filaments not obviously moniliform. Carposporophyte with six or more involucral filaments from the
basal cell of the female fertile filament or from the vegetative cell below

2

2a. Involucral cells of the carposporophytes about ten at maturity, originating from the vegetative cell
bearing the female fertile filament; tetrasporangia in clusters surrounded by involucral cells originating
directly from the vegetative cell

Griffithsia confervoides

2b. Involucral cells of the carposporophyte about six at maturity, developing from the basal cells of the
female fertile filament; tetrasporangia in clusters, the outer ring bearing involucral cells as well

Griffithsia subbiconica

References Griffithsia

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 27 November 2015.

 

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 December 2018.