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Electronic Flora of South Australia Genus Fact Sheet

Genus CLAUDEA Lamouroux 1813: 121

Phylum Rhodophyta – Family Delesseriaceae

Thallus with net-like fronds, unilaterally placed on short or long stipes developed from the "midrib" of the nets. Holdfast discoid to conical, pseudoparenchymatous; epilithic or epiphytic. Structure. Apices of fronds with a dome-shaped apical cell segmenting to give an axial filament, each cell with 4 pericentral cells, 2 lateral cells cut off first followed by 2 transverse pericentral cells; lateral pericentral cells developing second-order rows with their inner cells forming third-order rows, with all second and third-order rows reaching the blade margin; fourth-order rows occasionally present marginally. The lateral pericentral cells develop wings 1–2 mm broad. The upper (adaxial) transverse pericentral cells each produce a secondary blade with similar apical development, of which each adaxial transverse pericentral cell produces a row of cells which connect to the lower (abaxial) transverse pericentral cells of the secondary frond above, with all cells except the apical adherent one developing flat blades as in primary and secondary axes. These tertiary blades and their interstices form the network of the fronds and similar branching of the tertiary blades forms quaternary blades with smaller networks. Cortication of the axes commences some distance below the apices and becomes thick on lower axes from which the wings are lost.

Reproduction: Gametophytes dioecious. Procarps (in C. multifida) borne on abaxial transverse pericentral cells, usually on successive cells, with 2 sterile groups and a 4-celled carpogonial branch. Carposporophyte with a basal fusion cell, much branched gonimoblast, and clavate to ovoid terminal carposporangia. Cystocarps dome-shaped to ovoid, borne singly on distinct pedicels; pericarp ostiolate, corticate. Spermatangial sori formed on tertiary or quaternary blades, with sterile midribs and margins, with initials cut off from second- and third-order rows producing an outer layer of spermatangia.

Tetrasporangial sori formed on tertiary and quaternary blades, with tetrasporangia cut off from second-order cells in a single (or displaced to two) layer (from cortical cells also in C. multifida), with cover cells on each side of the blade dividing to form a continuous cortical layer; tetrasporangia subspherical, tetrahedrally divided.

Type species: C. elegans Lamouroux 1813: 121.

Taxonomic notes: A genus of 3 species, the type, C. multifida Harvey (1854, p. 145) from the northern Indian Ocean and C. batanensis Tanaka (1967, p. 18, figs 6–8) from the Philippines. Papenfuss (1937) gave a detailed description of the structure and reproduction of C. multifida.


HARVEY, W.H. (1854). New Algae from Ceylon. Journ. Bot. (Hooker) 6, 143–145, Plates 5–6.

LAMOUROUX, J.V.F. (1813). Essai sur les genres de la famille des thalassiophytes non articulées. Ann. Mus. Hist. Nat., Paris 20, 21–47, 115–139, 267–293, Plates 7–13.

PAPENFUSS, G.F. (1937). The structure and reproduction of Claudea multifida, Vanvoorstia spectabilis and Vanvoorstia coccinea. Synth. Bot. Upsal. 2(4): 1–66.

TANAKA, T. (1967). Some marine algae from Batan and Camiguin Islands, Northern Philippines — I. Mem. Fac. Fish. Kagoshima Univ. 16, 13–27.

The Marine Benthic Flora of Southern Australia Part IIID complete list of references.

Author: H. B. S. Womersley

Publication: Womersley, H.B.S. (24 February, 2003)
The Marine Benthic Flora of Southern Australia
Rhodophyta. Part IIID. Ceramiales – Delesseriaceae, Sarcomeniaceae, Rhodomelaceae
Reproduced with permission from The Marine Benthic Flora of Southern Australia Part IIID 2003, by H.B.S. Womersley. Australian Biological Resources Study, Canberra. Copyright Commonwealth of Australia.

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