Seaweeds of the South African South Coast

 

 

 

 

 

 

 

 

 

 

 

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Order Gigartinales

Family Solieriaceae

Rhabdonia natalensis Reinbold 1912: 199-200

Thalli red, terete, a few to 30 cm tall, rather lax. Axes slender and up to about 1 mm diameter, but up to 2 mm in lower axes; irregularly dichotomously branched, with up to 10 bifurcations per axis. Axis apices usually gradually pointed but may be rounded in (older?) specimens. Cystocarps ostiolate, forming as distinct globose swellings (about 1.5 mm diameter) just below the apices of terminal branchlets. In many specimens the branch tips remain visible on top of the cystocarps as tiny spines. Tetrasporangia not seen in BOL material.

Collections, ecology and regional distribution

Rather rare, having being found only near Port Alfred and at Cape Morgan (39-43), and apparently only in drift, indicating a subtidal habitat.

World distribution: also recorded from Mauritius (Boergesen 1943).

Lectotype locality: Kowie (Port Alfred), recorded by Papenfuss (1968): a note on Specimen 035362 in BOL, by Papenfuss, denotes it as “type”.

Note: We have only examined pressed herbarium specimens (BOL). R. natalensis has not been recorded in KZN. Norris points out that the epithet natalensis is probably based on Reinbold’s misconception about the location of the collecting site.

 

Rhabdonia natalensis, Kowie specimen (BOL).

Rhabdonia natalensis, Kowie specimen (BOL), showing apical branches and terminal cystocarps.

 

References Rhabdonia natalensis

Boergesen, F. 1943. Some marine algae from Mauritius. III. Rhodophyceae. Part 2. Gelidiales, Cryptonemiales, Gigartinales. Kongelige Danske Videnskabernes Selskab, Biologiske Meddelelser 19(1): 85, 42 figs, 1 plate.

Papenfuss G.F. 1968. Notes on South African marine algae 5. Journal of South African Botany 34 (5): 267-287.

Reinbold, T. 1912 In Tyson, W., 1912. New South African marine algae. Journal of Botany, London 50: 199-200.

 

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 November 2024.