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Order Gigartinales

Family Gigartinaceae

Gigartina insignis (Endlicher and Diesing) Schmitz in Barton 1896: 459

Thalli dark to blackish-red, leathery, branched, up to 20 (-40) cm tall. Holdfast a small disc; main axes compressed, up to about 2 (-3) cm wide, branching irregular to dichotomous, branches with numerous opposite or sub-opposite laterals one to a few mm long and about 1-2 mm wide. Thallus multiaxial; in cross-section medulla a network of branching cells, cortex of anticlinal filaments of small cells. Cystocarps visible as globose swellings about 2 mm in diameter, in lateral proliferations. Tetrasporangia developing in inner cortex, visible in fresh blades as small dark spots.

Collections, ecology and regional distribution

Collected from False Bay (Muizenberg) to Port Alfred, but apparently extends to at least Durban(18-51), where the type specimen was collected. There are many large specimens in BOL that were collected in drift, indicating a mainly subtidal vertical distribution.

World distribution: Endemic to South Africa.

Type locality: Port Natal (Durban), South Africa (Silva et al. 1996).

Note: This Gigartina species was not examined by Hommersand et al. (1993, 1994).

 


Gigartina insignis, female thallus, Kowie (BOL).


Gigartina insignis, female thallus, detail of margins showing papillae.


Gigartina insignis, male or vegetative thallus with no marginal papillae, Kowie (BOL).


Gigartina insignis, young plant from East London (BOL).


Gigartina insignis. 1. Habit. 2. Cross section. Reproduced from Stegenga et al. (1997).

 

References Gigartina insignis

Barton, E.S. 1896. Cape Algae. Journal of Botany, London, 35: 193-198, 458-461, 5 figs.

Hommersand, M. H., Fredericq, S. & D. W. Freshwater 1994. Phylogenetic systematics and biogeography of the Gigartinaceae (Gigartinales, Rhodophyta) based on the sequence analysis of rbcL. Botanica Marina 37: 193-203.

Hommersand, M. H., Guiry, M. D., Fredericq, S. & G. L. Leister. 1993. New perspectives in the taxonomy of the Gigartinaceae (Gigartinales, Rhodophyta). Hydrobiologia 260/261: 105-120.

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 21 November 2018.