Seaweeds of the South African South Coast

 

 

 

 

 

 

 

 

 

 

 

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Order Gigartinales

Family Phyllophoraceae

Gymnogongrus polycladus (Kützing) J. Agardh 1851

Gametophytic thalli stiff, erect, from a few to 10 cm tall, branching up to 6 times. Axes terete, dichotomies in the upper half fairly regular. Older axes often with some short, rather pointed lateral branches in secund or opposite series. Axes in small specimens less than 1 mm in diameter, in larger specimens up to 2 mm diameter. Apices tapered. Carposporophytes immersed, visible as swellings in main axes and sometimes in short side-branches. Sporophytes crustose (see Anderson & Bolton 1990 or description of G. glomeratus).

Collections, ecology and regional distribution

Found from False Bay eastwards to Cape Morgan (17-43), with the smaller “G. intermedius” form (see note below) recorded from Jongensfontein, Keurboomstrand and Port St Johns. Typically found in sand-influenced lower sublittoral zone.

World distribution: South Africa, Tristan da Cunha.

Type locality: Kalk Bay, False Bay (Silva et al. 1996).

Note: This species includes the former Gymnogongrus intermedius (Ahnfeltiopsis intermedia), which on the basis of DNA comparisons was shown to be a small form of G. polycladus (Fredericq et al 2003).

 

Gymnogongrus polycladus, herbarium specimen from Kowie (BOL).

Gymnogongrus polycladus, cross section of female thallus showing ostiole between the cystocarp and exterior.

Gymnogongrus polycladus, habit. Reproduced from Stegenga et al. (1997) (as Ahnfeltiopsis polycladus).

 

References Gymnogongrus polycladus

Agardh, J.G. 1851. Species genera et ordines algarum, seu descriptiones succinctae specierum, generum et ordinum, quibus algarum regnum constituitur. Volumen secundum: algas florideas complectens. Part 1. pp. [i]-xii, [1]-336 + 337-351 [Addenda and Indices]. Lundae [Lund]: C.W.K. Gleerup.

Anderson, RJ, & JJ Bolton. 1990. Reproductive morphology and life histories of southern African Gymnogongrus species (Rhodophyta, Phyllophoraceae). British Phycological Journal 25: 381-390.

Fredericq, S., Anderson, R.J & J. Lopez-Bautista. 2003. Systematic circumscription of some Phyllophoraceae from the Cape region, South Africa, based on morphological and molecular evidence. Proc. 17^th International Seaweed Symposium, Oxford University Press, pp. 263-273.

Silva, P.C., Basson, P.W. & Moe, R.L. 1996. Catalogue of the benthic marine algae of the Indian Ocean. University of California Publications in Botany 79: 1-1259.

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 18 November 2024.