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Order Ceramiales

Family Callithamniaceae

Callithamnion granulatum (Ducluzeau) C. Agardh 1828: 177

Plants (in the area) rarely more than 2 cm in length, as a rule epiphytic, with few erect axes and little or no creeping parts. Main axis in older parts fully corticated, with (much shorter) side branches roughly in four rows. Cells of main axis somewhat shorter to somewhat longer than broad, up to ca. 250 µm in diameter. Laterals branched from the first cell, with more or less recognizable main axis, in diameter ca. 75 µm at maximum, apical cells short and almost pointed without being acute. Tetrasporangia sessile on the cells of ultimate and penultimate branchlets, usually one per cell, measuring ca. 55 x 50 µm, tetrahedrally divided. Male stands one per cell, semiglobose, ca. 75 µm in diameter, producing many spermatangia on repeatedly branching systems of progressively smaller cells. Carposporophytes with twin gonimoblasts, the rounded lobes measuring ca. 200 µm in diameter at maturity, the individual carpospores ca. 40 µm across in largest diameter.

Collections, ecology and regional distribution

Recorded as a small epiphyte between Nature’s Valley and the Kei Mouth Area (31-43). It appears to be smaller than the plants that are described from Europe.

World distribution: widespread in the warm temperate and tropical Atlantic and Mediterranean.

Type locality: Hérault, France (Silva et al. 1996).


Callithamnion granulatum, with carposporophyte. (On Cladophora rugulosa, Haga Haga, stained slide).

Callithamnion granulatum, with tetrasporophyte. (On Cladophora rugulosa, Haga Haga, stained slide).

Callithamnion granulatum, thallus apex. (On Cladophora rugulosa, Morgan Bay, stained slide).

Callithamnion granulatum, with tetrasporangia, stained slide.

Callithamnion granulatum, with spermatangial stands, stained slide.


References Callithamnion granulatum

Agardh, C.A. 1828. Species algarum rite cognitae, cum synonymis, differentiis specificis et descriptionibus succinctis. Voluminis secundi. Sectio prior. pp. [i]-lxxvi, [i]-189. Gryphiae [Greifswald]: sumptibus Ernesti Mauriti [Ernst Mauritius].

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 19 April 2024.