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Order Peyssonneliales

Family Peyssonneliaceae

Peyssonnelia Decaisne

Thalli crustose, adhering to substrate to some degree, if only proximally attached then shaped like a bracket fungus; structure of basal layer of horizontally-spreading branched filaments producing dorsal ascending filaments that may be coherent or relatively loose, and ventral rhizoids that may be unicellular or multicellular; cells of erect filaments calcified to varying degrees depending on species. Reproductive structures grouped in sori on dorsal surface, reproductive cells interspersed among sterile paraphyses.

Identification of species often requires vertical longitudinal sections through thalli to determine structure of the basal cell layer. Members of this genus often among the deepest-growing seaweeds. Currently 71 species recognized worldwide (Guiry & Guiry 2013), including two certain records from our area, but see note.

Key to the species

1a. Crusts adhering tightly and almost completely to substratum; rhizoids unicellular

P. atropurpurea

1b. Thallus erect, comprising repeatedly branched axes a few mm wide

P. replicata

References Peyssonnelia

Guiry, M.D. & Guiry, G.M. 2013. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway.; searched on 27 September 2013.


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 19 April 2024.