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Electronic Flora of South Australia Species Fact Sheet

Laurencia majuscula (Harvey) Lucas 1935: 223.

Phylum Rhodophyta – Family Rhodomelaceae – Tribe Laurencieae

Selected citations: Cribb 1983: 120, pl. 37 fig. 3. Huisman 1997: 205; 2000: 171. Huisman & Walker 1990: 437. Huisman et al. 1990: 97. Kendrick et al. 1990: 48, 52. Lucas & Perrin 1947: 249. Millar & Kraft 1993: 54. Saito 1969: 149. Saito & Womersley 1974: 819, figs 1A, 6. Shepherd 1974: 27. Silva et al. 1996: 513. Womersley 1950: 188.


Laurencia obtusa sensu many authors, incorrect for southern Australian localities.

Laurencia obtusa var. majuscula Harvey 1863, synop.: xxvi.

Laurencia gracilis sensu Womersley 1950: 187.

Laurencia dendroides sensu Sonder 1880: 29.

Thallus (Fig. 202A) grey red to red-purple, 5–20 cm high, much branched, relatively soft and adherent to paper, with one to several percurrent, usually bushy, axes, pyramidal to spreading; branching irregularly radial, branches terete, axes (0.7–) 1–2 mm in diameter, grading to ultimate ramuli 0.5–2 (–4) mm long and 0.2–0.5 mm in diameter; most branches less than 2 mm apart except where denuded. Holdfast discoid, 1–2 (–3) mm across, becoming stoloniferous; epilithic or epiphytic. Structure. Epidermal cells near apices (Fig. 205A) with convex, slightly projecting, outer walls, 15–25 µm in diameter near apices, extending to 35 (–50) µm broad and L/D 2–4 on lower axes, usually in longitudinal rows, with lateral pit-connections, corps en cerise present; in transverse section epidermal cells L/D 1–1.5, inner cells with intercellular spaces, but thickenings absent. Cells with discoid to elongate rhodoplasts.

Reproduction: Gametophytes dioecious. Carposporophytes with a basal fusion cell and short, branched gonimoblast with clavate terminal carposporangia 40–75 µm in diameter. Cystocarps (Fig. 202B) often clustered, sessile, subspherical to ovoid, 0.5–1 mm in diameter; pericarp ostiolate, corticated, with a slight neck. Spermatangial receptacles (Fig. 202C) single or clustered, 400–900 µm across, spermatangia borne on trichoblasts.

Tetrasporangial ramuli (Fig. 202D) simple or compound, terete, 150–300 (–500) µm in diameter and 0.2–0.8 (–2) mm long, cut off abaxially from cortical cells in parallel arrangment, tetrasporangia 70–100 µm in diameter.

Type from Rottnest I., W. Aust.; lectotype in Herb. Harvey, TCD (Alg. Aust. Exsicc. 236a).

Selected specimens: Port Denison, W. Aust., drift (Kraft, 14.xii.1971; AD, A42016). Strickland Bay, Rottnest I., W. Aust., on Sargassum, reef surface (Womersley, 5.ix.1979; AD, A51084). D'Entrecasteaux Reef, S. Aust., 15–20 m deep, epiphytic (Shepherd, 27.iii.1980; AD, A52160). Coffin Bay, S. Aust., upper sublittoral (Womersley, 24.ii.1959; AD, A22565. Billy Lights Point, Port Lincoln, S. Aust., uppermost sublittoral (Womersley, 12.i.1984; AD, A54734-"Marine Algae of southern Australia" No. 316). Marino, S. Aust., drift (Womersley, 23.i.1972; AD, A41262). Aldinga, S. Aust., reef pools (Womersley, 16.i.1972; AD, A41231). American R. inlet, Kangaroo I., S. Aust., on shells, 2–3 m deep (Saito, 7.iv.1972; AD, A41966). Flinders, Western Port, Vic., drift (Sinkora A1731, 16.xi.1972; AD, A43905). Lady Barron, Flinders I., Bass Strait (Perrin, 12.vi.1949; AD, A50206). Crayfish Point, Taroona, Tas., 5 m deep (Brown, 24.x.1982; AD, A55773).

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

Distribution: Widespread around Australia, usually in sheltered situations. Widespread in the Indian Ocean (see Silva et al. 1996, p. 513).

Taxonomic notes: Laurencia majuscula is variable in habit, with some specimens being placed as var. elegans (Lucas) Saito & Womersley (1974, p. 821).


CRIBB, A.B. (1983). Marine algae of the southern Great Barrier Reef—Part I. Rhodophyta. (Aust. Coral Reef Soc., Handbook 2: Brisbane.)

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

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.

HUISMAN, J.M. (1997). Marine Benthic Algae of the Houtman Abrolhos Islands, Western Australia. In Wells, F.E. (Ed.) The Marine Flora and Fauna of the Houtman Abrolhos Islands, Western Australia, pp. 177–237. (W. Aust. Museum: Perth.)

HUISMAN, J.M. (2000). Marine Plants of Australia. (Univ. W. Aust. Press, Nedlands, W. Aust. & ABRS, Canberra, A.C.T.)

HUISMAN, J.M., KENDRICK, G.A., WALKER, D.I. & COUTÉ, A. (1990). The Marine Algae of Shark Bay, Western Australia. Research in Shark Bay. Report of the France-Australe Bicentenary Expedition Committee, pp. 89–100.

KENDRICK, G.A., HUISMAN, J.M. & WALKER, D.I. (1990). Benthic macroalgae of Shark Bay, Western Australia. Bot. Mar. 33, 47–54.

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

LUCAS, A.H.S. (1935). The marine algae of Lord Howe Island. Proc. Linn. Soc. N.S. W. 60, 194–232, Plates 5–9.

MILLAR, A.J.K. & KRAFT, G.T. (1993). Catalogue of marine and freshwater Red Algae (Rhodophyta) of New South Wales, including Lord Howe Island, South-western Pacific. Aust. Syst. Bot. 6, 1–90.

SAITO, Y. & WOMERSLEY, H.B.S. (1974). The southern Australian species of Laurencia (Ceramiales: Rhodophyta). Aust. J. Bot. 22, 815–874.

SAITO, Y. (1969). The algal genus Laurencia from the Hawaiian Islands, the Philippine Islands and adjacent areas. Pacif. Sci. 23, 148–160.

SHEPHERD, S.A. (1974). An underwater survey near Crag Point in upper Spencer Gulf. Dept. Fisheries, S.Aust. Tech. Rep. No. 1.

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

SONDER, O.W. (1880). In Mueller, F., Fragmenta Phytographiae Australiae. Supplementum ad volumen undecinum: Algae Australianae hactenus cognitae, pp. 1–42, 105–107. (Melbourne.)

WOMERSLEY, H.B.S. (1950). The marine algae of Kangaroo Island. III. List of Species 1. Trans. R. Soc. S. Aust. 73, 137–197.

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

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.

Illustrations in Womersley Part IIIA, 2003: FIG. 202, 205A.

Figure 202 image

Figure 202   enlarge

Fig. 202. Laurencia majuscula (A, AD, A41262; B–D, AD, A41231). A. Habit. B. Cystocarpic thallus. C. Spermatangial thallus. D. Tetrasporangial thallus. (B–D, as in Saito & Womersley 1974, courtesy of Aust. J. Bot)

Figure 205 image

Figure 205   enlarge

Fig. 205. A. Laurencia majuscula (AD, A41231). Transverse section. B. Laurencia aldingensis (AD, A44448). Longitudinal section. C. Laurencia forsteri (AD, A41855). Transverse section with lenticular thickenings. D. Laurencia clavata (AD, A42231). Longitudinal section. E. Laurencia shepherdii (AD, A42795). Longitudinal section. F. Laurencia arbuscula (AD, A42244). Transverse section. (All as in Saito & Womersley 1974, courtesy of Aust. J. Bot.)

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