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Ceramium rubrum C. Agardh 1811: 17, nom. cons. prop. J.

Phylum Rhodophyta – Order Ceramiales – Family Ceramiaceae – Tribe Ceramieae

Selected citations: Agardh 1851: 127; 1876: 100; 1894: 37. De Toni 1903: 1476. Garbary et al. 1978: 85. Harvey 1844: 449; 1855a: 557; 1859b: 330; 1863, synop.:xlvii. Hooker & Harvey 1847: 409. Huisman & Walker 1990: 422. Kylin 1944: 69, pl. 20, fig. 60. Newton 1931: 400, fig. 239. Reinbold 1897: 61. Silva et al. 1996: 402. Sonder 1848: 167; 1881: 12. Tate 1882: 17. Tisdall 1898: 503. Wilson 1892: 185. Womersley 1978: 217, figs 2A, 7.


Ceramium divergens sensu Guiler 1952: 98. Lucas 1909: 53; 1929a: 26.

Ceramium rubrum var. proliferum J. Agardh 1876: 100. Sonder 1855: 514.

Ceramium rubrum var. pygmaeum Sonder 1848: 167.

Ceramium flagelliferum Kützing 1849: 686; 1863: 4, pl. 8e-g. Sonder 1853: 676.

C. nobile J. Agardh 1894:41. De Toni 1903: 1480. De Toni & Forti 1922: 56. Guiler 1952: 98. Laing 1927: 176. Lucas 1909: 53; 1929a: 26; 1929b: 53. Lucas & Perrin 1947: 369. Naylor 1954: 659. Reinbold 1898: 51.

C. subcartilagineum J. Agardh 1894: 24. De Toni 1903: 1463. Ewart 1907:91. Guiler 1952: 99. Levring 1946: 224. Lucas 1909: 53; 1929a: 26; 1929b: 53. Lucas & Perrin 1947: 367.

C. nodulosum (Lightfoot) Ducluzeau. Maggs & Hommersand 1993: 64.

Thallus (Pl. 2, fig. 3; Fig. 179A) medium to dark red, 5–15 (–25) cm high, branching frequent to relatively sparse, subdichotomous (especially near apices) or irregularly lateral, often with numerous small proliferous branchlets below; main branches sometimes slightly moniliform due to denser cell formation at the nodes and slightly swollen axial cells. Branches 0.5–1 mm in diameter below, 200–500 µm in diameter above, tapering only slightly until near the apices which are slightly involute to straight. Base usually single, erect, attached by a tuft of rhizoids originating from periaxial cells; epilithic or epiphytic on seagrasses or larger algae. Structure. Axial cells L/D 0.5–1, becoming completely corticated (Figs 179B, C, 182A) close to the apices, with the terminal cells of both the acropetal and basipetal corticating filaments becoming angular and dovetailing together to obscure the join. Periaxial cells 7 (–8), each cutting off usually two cells acropetally and basipetally, continuing as corticating filaments often with two divisions if space permits; these inner cortical cells enlarge and elongate to L/D 3–5 (Fig. 179C); in some plants short acropetal filaments from the periaxial cells project outwardly. Outer cortex present, varying from a fairly complete cover to small cells lying largely over the margins of the inner cells but not usually forming rosettes except over the rounded periaxial cells (Fig. 179C). Hairs from the outer cortical cells often present in young parts. Rhodoplasts discoid in small cells, ribbon like in axial cells.

Reproduction: Gametophytes dioecious. Carposporophytes (Fig. 179D) 200–450 µm across, closely surrounded by 2–5 (–8) short, curved, involucral branchlets, carposporangia ovoid, 20–30 µm in diameter. Spermatangia covering the surface of branches, arising first on the adaxial side.

Tetrasporangia (Fig. 179E) cut off at first from the the periaxial cells or the immediate cortical derivatives and thus in rings of 10–15 sporangia along the branches, later from any inner cortical cell and thus scattered, variable in size (30–60 µm in diameter), spherical to ovoid, more or less cruciately divided, protruding slightly to moderately within the cortex and surrounded (in face view) by a rosette of outer cortical cells.

Type from Britain. Neotype to be selected (see Silva et al. 1996, p. 403).

Selected specimens: Elliston, S. Aust., 10m deep (Shepherd, 18.x.1973; AD, A44204). Point Avoid, S. Aust., drift (Womersley, 2.xii.1975; AD, A46912). Between Thistle and Hopkins Is, Spencer Gulf, S. Aust., on Lenormandiopsis latifolia, 6–10m deep (Baldock, 1.i.1964; AD, A27123). Haystack I., Althorpe Is, S. Aust., 10m deep (Baker, 29.x.1993; AD A65522). Port Noarlunga, S. Aust., on Gulsonia annulata, drift (Womersley, 30.xii.1975; AD, A47024). American R. inlet, Kangaroo I., S. Aust., 4–6m deep (Womersley, 22.viii.1963; AD, A26973). Muston, Kangaroo I., S. Aust., upper sublittoral (Womersley, 27.viii.1950; AD, A15367). Robe, S. Aust., drift (Womersley, 15.iv.1994; AD, A63552). Port Fairy, Vic. (Lucas, Jan. 1932; AD, A48236). Swan Bay, Port Phillip, Vic., lm deep (Watson, 6.x.1973; AD, A44147). Walkerville, Vic., drift (Sinkora A1573, 9.iii.1972; AD, A43148). Crawfish Rock, Westernport Bay, Vic., 5–8m deep (Watson, 28.v.1974; AD, A45445). Low Head, Tas., on Gracilaria (Perrin, 24.vi.1951; AD, A48190). Great Taylor Bay, Bruny L, Tas., on Polysiphonia cancellata, 1–2m deep (Shepherd, 14.ii.1972; AD, A42148). Southport, Tas., on Codium, upper sublittoral (Cribb 62.3, 19.vi.1950; AD, A16366). Cloudy Lagoon, SE Tas., on Rhodoglossum, 1–3m deep (Edgar; 12.ii.1995; AD, A64230).

Distribution map based
on current data relating to
specimens held in the
State Herbarium of SA

Distribution: A widely distributed species in temperate regions, especially in the northern Atlantic and probably present in most oceans.

Fremantle, W. Aust (MEL, 45384) to Wilsons Prom., Vic., and arround Tasmania. Usually confined to areas of calm to moderate water movement, and is probably more widespread around the Australian coast.

Taxonomic notes: Conservation of the name C. rubrum is advocated by Silva et al. (1996, p. 403).

Australian plants were referred to C. rubrum by early authors (see above) and by Harvey on herbarium sheets as C. rubrum australe, but were separated as a distinct species, C. flagelliferum, by Kützing (1849), based on plants from Tasmania (V.D.L.; Hooker, type in L, 938, 303...214). J. Agardh (1894) later described this species as both C. nobile and C. subcartilaginium. These names were discussed by Womersley (1978, p. 219).

While Australian specimens referred to C. rubrum are relatively uniform, it is closely related to C. pusillum Harvey, differing in being larger with dichotomous or irregular and often proliferous branching, by the nodal cortical bands uniting relatively close to the apices with the cells usually dovetailing together, by the inner cortical cells becoming elongate in older parts with the outer cortical cells varying from a largely complete cover to rows along the larger inner cells but not forming distinct rosettes (except often around the periaxial cells), by the tetrasporangia usually developing from any inner cortical cell as well as the periaxial cells and thus on older parts appearing scattered, and by being generally a species of calm to moderate (often deeper) water movement.

While no one of the above features clearly distinguishes C. rubrum from C. pusillum, overall assessment of them permits ready separation of nearly all specimens of these taxa.

Ceramium divergens J. Agardh (1894, p. 27) was described from New Zealand (Invercargill) and Tasmania. The Tasmanian record was repeated by Lucas (1909, p. 53; 1929a, p. 26) and Guiler (1952, p. 98). J. Agardh's description was based largely on the New Zealand specimens, of which LD, 21108 is a suitable lectotype. The Tasmanian specimens are almost certainly not C. divergens, which is completely corticated but with the older branches showing smaller cortical cells when the nodal cortication joins and with numerous short proliferous branchlets with divergent apices. Pending re-examination of the Tasmanian specimens of J. Agardh, they are provisionally referred to C. rubrum.


AGARDH, C.A. (1811). Dispositio Algarum Sueciae. pp. 17–26. (Berling: Lund.)

AGARDH, J.G. (1851). Species Genera et Ordines Algarum. Vol. 2, Part 1, I-XII, 1–336 + index. (Gleerup: Lund.)

AGARDH, J.G. (1876). Species Genera et Ordines Algarum. Vol. 3, Part 1- Epicrisis systematic Floridearum, pp. i-vii, 1–724. (Weigel: Leipzig.)

DE TONI, G.B. (1903). Sylloge Algarum omnium hucusque Cognitarum. Vol. 4. Florideae. Sect. 3, pp. 775–1521 + 1523–1525. (Padua.)

EWART, A.J. (1907). Notes on a collection of marine algae from King Island. Vic. Nat. 23, 90–92.

GARBARY, D.J., GRUND, D. & McLACHLAN, J. (1978). The taxonomic status of Ceramium rubrum (Huds.) C. Ag. (Ceramiales, Rhodophyceae) based on culture experiments. Phycologia 17, 85–94.

GUILER, E.R. (1952). The marine algae of Tasmania. Checklist with localities. Pap. Proc. R. Soc. Tasmania 86, 71–106.

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

HARVEY, W.H. (1855a). Some account of the marine botany of the colony of Western Australia. Trans. R. Jr. Acad. 22, 525–566.

HARVEY, W.H. (1859b). Algae. In Hooker, J.D., The Botany of the Antarctic Voyage. III. Flora Tasmaniae. Vol. II, pp. 282–343, Plates 185–196. (Reeve: London.)

HARVEY, W.H. (1863). Phycologia Australica. Vol. 5, Plates 241–300, synop., pp. i-lxxiii. (Reeve: London.)

HOOKER, J.D. & HARVEY, W.H. (1847). Algae Tasmanicae. Lond. J. Bot. 6, 397–417.

HUISMAN, J.M. & WALKER, D.I. (1990). A catalogue of the marine plants of Rottnest Island, Western Australia, with notes on their distribution and biogeography. Kingia 1, 349–459.

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

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LAING, R.M. (1927). A reference list of New Zealand marine algae. Trans. Proc. N.Z. Inst. 57, 126–185.

LEVRING, T. (1946). A list of marine algae from Australia and Tasmania. Acta Horti gothoburg 16, 215–227.

LUCAS, A.H.S. & PERRIN, F. (1947). The Seaweeds of South Australia. Part 2. The Red Seaweeds. (Govt Printer: Adelaide.)

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LUCAS, A.H.S. (1929b). A census of the marine algae of South Australia. Trans. R. Soc. S. Aust. 53, 45–53.

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REINBOLD, T. (1897). Die Algen der Lacepede und Guichen Bay und deren näherer Umgebung (Süd Australien), gesammelt von Dr. A. Engelhart-Kingston. Nuova Notarisia 8, 41–62.

REINBOLD, T. (1898). Die Algen der Lacepede und Guichen Bay (Slid Australien) und deren näherer Umgebung, gesammelt von Dr. A. Engelhart-Kingston. II. Nuova Notarisia 9, 33–54.

SILVA, P.C., BASSON, P.W. & MOE, R.L. (1996). Catalogue of the Benthic Marine Algae of the Indian Ocean. (University of California Press: Berkeley, Los Angeles & London.)

SONDER, O.W. (1848). Algae. In Lehmann, C., Plantae Preissianae. Vol. 2, pp. 161–195. (Hamburg.)

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SONDER, O.W. (1881). In Mueller, F., Fragmenta Phytographiae Australiae. Supplementum ad volumen undecinum: Algae Australianae hactenus cognitae, pp. 1–42, 105–107. (Melbourne.)

TATE, R. (1882). A list of the charas, mosses, liverworts, lichens, fungs, and algals of extratropical South Australia. Trans. R. Soc. S. Aust. 4, 5–24.

TISDALL, H.T. (1898). The algae of Victoria. Rep. 7th Meet. Aust. Ass. Adv. Sci., Sydney, 1898, pp. 493–516.

WILSON, J.B. (1892). Catalogue of algae collected at or near Port Phillip Heads and Western Port. Proc. R. Soc. Vict. 4, 157–190.

WOMERSLEY, H.B.S. (1978). Southern Australian species of Ceramium Roth (Rhodophyta). Aust. J. Mar. Freshw. Res. 29, 205–257.

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

Author: H.B.S. Womersley

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

Illustrations in Womersley Part IIIA, 1998: PLATE 2 fig. 3; FIGS 179, 182A.

Plate 2 image

Plate 2   enlarge

PLATE 2 fig. 1. Anotrichium elongatum at Robe, S. Aust. (AD, A63206).
fig. 2. Euptilota articulata at Rottnest I., W.Aust. (MURU, JH727). Photo: J.M. Huisman.
fig. 3. Ceramium rubrum at Cloudy Lagoon, SE Tas. (AD, A64230). Photo: G. Edgar.
fig. 4. Ceramium excellens at Cloudy Lagoon, SE Tas. (AD, A64234). Photo: G. Edgar.

Figure 179 image

Figure 179   enlarge

Fig. 179. Ceramium rubrum (A, AD, A46912; B–E, AD, A47024). A. Habit of female (left) and tetrasporangial (right) plants. B. Cortication of young branch. C. Cortication of older branch showing rosettes around periaxial cells and elongate inner cortical cells. D. Carposporophyte with involucral branches. E. Tetrasporangial branch. (All as in Womersley 1978, courtesy of Aust. J. Mar. Freshw. Res.)

Figure 182 image

Figure 182   enlarge

Fig. 182. A. Ceramium rubrum (AD, A47024). Part of a branch 19-21 segments from apex, showing "dovetailing" of cortical cell filaments giving complete cortication. B. Ceramium pusillum (AD, A33116). Part of a branch 21-24 segments from apex, showing slight internodal spaces between nodal cortication. C. Ceramium lenticulare (AD, A45063). Segments of a branch showing cortical cell lineages and lenticular internodal spaces. D. Ceramium excellens (AD, A38371). Nodal cortication showing cortical cell lineages and internodal space. E. Ceramium tasmanicum (AD, A42758). Young nodal cortication showing cell lineages. (All as in Womersley 1978, courtesy of Aust. J. Mar. Freshw. Res.)

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