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Electronic Flora of South Australia Species Fact Sheet

Sargassum sonderi (J. Agardh) J. Agardh 1872: 59; 1889: 44, p1. 14 figs 1,2.

Phylum Phaeophyta – Order Fucales – Family Sargassaceae

Selected citations: Grunow 1915: 332. Womersley 1954b: 346, fig. 1d, pl. 3.


Cystophora sonderi J. Agardh 1848: 247.

Phyllotrichia sonderi (J. Agardh) Areschoug 1854: 332.

Thallus (Fig. 158B) medium brown, 10–50 cm long, with simple or occasionally branched stipes 2–15 (–22) cm long, compressed, 2–6 mm broad, with prominent, distichous, branch residues, bearing apically and distichously 2–8 (–12) primary branches. Holdfast discoid-conical, 5–20 mm across, with one to several stipes; epilithic. Primary branches 5–40 cm long, radially branched, much divided, with angular but not compressed axes. Laterals (lower) pinnate, 3–6 (–10) cm long, with linear branches 1–3 cm long and 2–4 (–5) mm broad; upper laterals much divided, becoming filiform above, terete to compressed, 1–3 cm long. Vesicles developing in mid winter, petiolate, subspherical, 1–2 (–3) mm in diameter, mutic or with a slender apical mucro.

Reproduction: Thalli monoecious. Receptacles (Fig. 160D) in racemose clusters on upper ramuli, petiolate, simple, shortly lanceolate, smooth, 1–2 mm long and 500–800 µm in diameter, with scattered ostioles. Conceptacles unisexual or bisexual; oogonia sessile, subspherical to ovoid, 200–320 µm long and 150–240 µm in diameter, few per conceptacle; antheridia sessile or on branched paraphyses, ovoid, 18–28 µm long and 8–12 µm in diameter.

Type from W. Aust. (Preiss); in Herb. Agardh, LD, 2043.

Selected specimens: Cowaramup Bay, W. Aust., drift (Smith, Aug. 1962; UWA). Elliston, S. Aust., 10–11 m deep in bay (Shepherd, 7.x.1974; ADU, A45986) and 5 m deep (Shepherd, 13.v.1971; ADU, A38632). Rapid Head, S. Aust., 3–8 m deep (Shepherd, 30.xii.1969; ADU,

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

Distribution: From Cowaramup Bay, W. Aust., to Wilsons Prom., Vic., and around Tasmania.

Taxonomic notes: A35196). D'Estrees Bay, Kangaroo I., S. Aust., outer reef pools (Womersley, 1.i.1950; ADU, Al2814). Pennington Bay, Kangaroo I., S. Aust., drift ( Womersley, 20.v.1945; ADU, A2418). Observation Point, Port Phillip, Vic., 5 m deep (Macpherson, 18.i.1959; ADU, A23206). Low Head, Tas. (Perrin, Aug. 1948; ADU, A9314). Curries R., Tas. (Perrin 290, 17.ii.1948; ADU, A47147). Orford, Tas., drift (Wollaston & Mitchell, 1.iii.1964; ADU, A27757).

The upper fertile parts of S. sonderi are very similar to those of S. decipiens, but the two species are clearly separated by the pinnately branched, long, lower laterals of the former, and short, little-branched, lower laterals of the latter. Some plants of S. sonderi are probably, from stipe length, 12–20 years old.


AGARDH, J.G. (1848). Species, Genera et Ordines Algarum. Vol. 1. (Gleerup: Lund.)

AGARDH, J.G. (1872). Till algernes systematik. Ada Univ. lund. 9(8), 1–71.

AGARDH, J.G. (1889). Species Sargassorum Australiae. K. Svenska Vetenskapsakad. Handl. 23(3), 1–133, Plates 1–31.

ARESCHOUG, J.E. (1854). Phyceae novae et minus cognitae in maribus extraeuropaeis collectae. Ada Reg. Soc. Sci. Upsala, Ser. III, 1, 329–372.

GRUNOW, A. (1915). Additamenta ad cognitionem Sargassorum. Verh. Zool. -Bot. Wien 65, 329–448.

WOMERSLEY, H.B.S. (1954b). Australian species of Sargassum, subgenus Phyllotrichia. Aust. J. Bot. 2, 337–354, Plates 1–5.

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

Author: H.B.S. Womersley

Publication: Womersley, H.B.S. (14 December, 1987)
The Marine Benthic Flora of Southern Australia
Part II
©Board of the Botanic Gardens and State Herbarium, Government of South Australia

Illustrations in Womersley Part II, 1997: FIGS 158B, 160D.

Figure 158 image

Figure 158   enlarge

Fig. 158. A. Sargassum decipiens (ADU, A42786). B. Sargassum sonderi (ADU, A38632).

Figure 160 image

Figure 160   enlarge

Fig. 160. Receptacles of species of Sargassum subgenus Phyllotrichia. A. Sargassum decurrens (ADU. A53922). B. Sargassum heteromorphum (ADU, A23954). C. Sargassum decipiens (ADU, A57476). D. Sargassum sonderi (ADU, A9314). E. Sargassum varians (ADU, A55724). F. Sargassum verruculosum (ADU. A18826).

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