Valid XHTML 1.0 Transitional

Order Corallinales

Family Corallinaceae

Sub-family Corallinoideae

Amphiroa rigida J.V. Lamouroux 1816: 297, pl. XI: fig. 1

Plants pink to grayish, 2-3 (-5) cm tall, terete, dichotomously branched, somewhat delicate. Genicula barely visible or invisible to naked eye. Intergenicula 2-4 mm long and about 0.5 mm diameter, cylindrical but slightly flattened at tips. Conceptacles 200-300 µm in diameter. Branching in some specimens at fairly wide angle (40-50o).

Collections, ecology and regional distribution

From Walker Point (Buffalo Bay) to at least Black Rock in northern KZN (29-58).

World distribution: Also recorded from Tanzania (Oliveira et al. 2005) and Mauritius (Silva et al. 1996) and widely distributed in temperate and tropical waters (Guiry & Guiry 2014).

Type locality: Meditterranean Sea (Silva et al. 1996).

Note: this seldom-collected species may be rare or overlooked on account of its small size and tendency to occur in turfs. On the south coast it is only recorded from Walker Point, Kowie Estuary, and Mzamba. We have not seen “some anastomoses between contacting branches” that Oliveira et al. (2005) noted in Tanzanian material. This taxon was not among the South African species examined in the barcoding study of Kogame et al. (2017), and requires further study.


Amphiroa rigida, Palm Beach, KZN (BOL). Scale on left in mm. A tiny Jania sp. is visible in the middle of the Amphiroa thallus.

Amphiroa rigida, Palm Beach, KZN (BOL). Detail showing wart-like conceptacles on many segments.

Amphiroa rigida, typical tangled turf specimens, Tsitsikamma (BOL). Scale on left in mm.


References Amphiroa rigida

Guiry, M.D. & Guiry, G.M. 2014. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway.; searched May 2014.

Kogame, K., Uwai, S., Anderson, R.J., Choi, H-G. & J.J. Bolton. 2017. DNA barcoding of South African geniculate coralline red algae (Corallinales, Rhodophyta). South African Journal of Botany 108: 337-341.

Lamouroux, J.V.F. 1816. Histoire des polypiers coralligènes flexibles, vulgairement nommés zoophytes. pp. [i]-lxxxiv, chart, [1]-560, [560, err], pls I-XIX, uncol. by author. Caen: De l'imprimerie de F. Poisson.

Oliveira, E., Österlund, K. & Mtolera, M.S.P. 2005. Marine Plants of Tanzania. A field guide to the seaweeds and seagrasses. pp. 267, Numerous coloured illustrations and line drawings. Stockholm: Botany Department, Stockholm University.

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.


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 26 February 2024.