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Order Ceramiales

Family Delesseriaceae

Acrosorium acrospermum (J. Agardh) Kylin 1924: 78

Plants bright red, up to 5 cm tall, fan-shaped, rather delicate. Blades variously incised, lobed, rather contorted, monostromatic except at the base and in veins. Tetrasporangia in patches of sori near the edges of blades; cystocarps scattered on blades, distinctly swollen, with single prominent ostiole.

Collections, ecology and regional distribution

Found from the southern Cape Peninsula to Cape Vidal area in northern Kwazulu-Natal (17-56). Epilithic or often epiphytic in rock pools, lower eulittoral and shallow sublittoral zones.

World distribution: Also recorded from Namibia (Rull Lluch 2002) and St Paul Island (Silva et al. 1996).

Type locality: “In mari Capense” (South Africa) (Silva et al. 1996).


  1. Papenfuss (1939) described the reproductive morphology of this species in detail.
  2. Stegenga et al. (1997) point out that this species is strikingly similar to A. maculatum except for the occurrence of pale spots in blades of the latter.
  3. South coast specimens are in general smaller than some of the large specimens collected from the west coast.


Acrosorium acrospermum, well-developed thalli on sandy worm tube. Cystocarps arrowed.

Acrosorium acrospermum, detail of cells and vein (surface view).

Acrosorium acrospermum, habit, tetrasporangial. Reproduced from Stegenga et al. (1997).


References Acrosorium acrospermum

Kylin H. 1924. Studien über Delesseriaceeen. Lunds Universitets Årsskrift, N.F. Avd 2, 20 (6): 1-111.

Papenfuss GF. 1939. The development of the reproductive organs in Acrosorium acrospermum. Botaniska Notiser 1939: 11-20.

Rull Lluch, J. 2002. Marine benthic algae of Namibia. Scientia Marina 66 (Supplement 3): 258 pp.

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,; Accessed on 02 March 2024.