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Order Halymeniales

Family Halymeniaceae

Pachymenia cornea (Kützing) Chiang 1970: 22-24, fig. 8

Plants red to purplish-red, foliose, orbicular to irregular in outline, up to about 30 (-40) cm in diameter, rather cartilaginous in texture: margins thickened and dentate, sometimes forming a double margin. Cortex of anticlinal rows of filaments, outermost cortical cells about 5 µm long and 1.0-1.5 µm in diameter; medulla of densely-packed filaments running in all directions. Tetrasporangia scattered in cortical layer of thallus, about 25 µm long, cruciately to decussately divided. Cystocarps immersed in thallus, apparently without ostiole.

Collections, ecology and regional distribution

Recorded from Namibia along the entire west coast of South Africa to East London (1-41). Epilithic in the sublittoral zone and recorded to at least 24 m depth in Tsitsikamma.

World distribution: Southern African endemic.

Type Locality: Cape Agulhas, South Africa (Chiang, 1970).


Pachymenia cornea, typical False Bay specimen.

Pachymenia cornea, bright orange-red specimen, Kenton-on-Sea.

Pachymenia cornea, XS of Kenton-on-Sea specimen above, showing cortex of anticlinal filaments and part of medulla of multi-directional filaments.

Pachymenia cornea, 1. Habit. 2. Cross section of cortex. Reproduced from Stegenga et al. (1997).


References Pachymenia cornea

Chiang, Y-M. 1970. Morphological studies of red algae of the family Cryptonemiaceae. University of California Publications in Botany 58: 95 pp.

Stegenga, H., Bolton, J.J. and 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,; Accessed on 02 March 2024.