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Electronic Flora of South Australia Genus Fact Sheet

Genus CARPOTHAMNION Kützing 1849: 668

Phylum Rhodophyta – Order Ceramiales – Family Ceramiaceae – Tribe Callithamnieae

Thallus erect, 2–32 cm high, much branched irregularly, with ecorticate apical tufts of slender, alternate, spirally branched axes and determinate lateral branchlets, with dense, pseudoparenchymatous, rhizoidal cortication from shortly below the apical tufts, surrounding a large celled axial filament; holdfast first discoid, developing branched haptera. Cells uninucleate.

Reproduction: Gametophytes dioecious. Procarps on intercalary cells of ecorticate axes, with two opposite periaxial cells, one bearing a 4-celled carpogonial branch; sterile cells absent. Fertilized carpogonium fusing with both auxiliary cells via connecting cells, producing twinned carposporophytes with basal foot cells; involucral branchlets absent. Spermatangia borne on cells of determinate branchlets, with initials cutting off intermediate cells and then spermatangia.

Tetrasporangia borne on cells of the determinate branchlets, sessile, tetrahedrally divided.

Type species: C. gunnianum Kützing 1849: 668.

Taxonomic notes: Thamnocarpus Harvey (1844, p1.662), a generally used name for this genus, was proposed for conservation by Silva (1950, p. 270), but this proposal was not accepted and the name remains as Carpothamnion Kützing. The type species was described in detail by Wollaston (1992), who recognised a second species from Africa.

Carpothamnion is characterised by callithamnioid reproduction but with a dense, pseudoparenchymatous cortex surrounding the large axial filament, arising shortly below the apices.


HARVEY, W.H. (1844). Algae of Tasmania. Lond. J. Bot. 3, 428–454.

KÜTZING, F.T. (1849). Species Algarum. (Leipzig.)

SILVA, P.C. (1950). Generic names of algae proposed for conservation. Hydrobiologia 2, 252–280.

WOLLASTON, E.M. (1992). Morphology and taxonomy of Thamnocarpus (Ceramiaceae, Rhodophyta) in southern Australia and east Africa. Phycologia 31, 138–146.

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

Author: H.B.S. Womersley & E.M. Wollaston

Publication: Womersley, H.B.S. (24 December, 1998)
The Marine Benthic Flora of Southern Australia
Rhodophyta. Part IIIC. Ceramiales – Ceramiaceae, Dasyaceae
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