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Electronic Flora of South Australia Species Fact Sheet

Dictyomenia sonderi Harvey 1858: pl. 21; 1863, synop.: xvii.

Phylum Rhodophyta – Family Rhodomelaceae – Tribe Pterosiphonieae

Selected citations: J. Agardh 1863: 1082; 1885: 105. De Toni 1903: 986. De Toni & Forti 1923: 43. Falkenberg 1901: 285, pl. 19 figs 13–16. Huisman 1997: 204; 2000: 163. Huisman & Walker 1990: 434. Kützing 1864: 34, pl. 96. Kylin 1956: (525), figs 378E, F, 418. Lewis 1984: 53. Lucas 1909: 42. Lucas & Perrin 1947: 280, fig. 127. May 1965: 396. Schmitz & Falkenberg 1897: 445, fig. 248. Shepherd & Sprigg 1976: 170. Shepherd & Womersley 1981: 367. Silva et al. 1996: 489. Sonder 1880: 33.


Dictyomenia fimbriata Greville sense Harvey 1855a: 538.

Dictyomenia sonderiana J. Agardh 1897: 59.

Thallus (Fig. 151A) medium to dark red-brown, erect, 10–40 cm high, complanately and marginally branched with regularly to irregularly pinnate lateral branches, linear and (3–) 4–6 (–7) mm broad, with regular marginal fringes of branched determinate laterals 1–2 (–3) mm long. Main branches (Fig. 151B) with a well defined midrib and prominent alternate lateral veins, midrib thickened below and remaining as a subterete stalk 1–1.5 (–2) mm thick where the lateral membrane is lost. Branch blades corticated from close to apices. Holdfast fibrous, branched, 1–2 cm across; epilithic. Structure. Apical cell (Fig. 151C) of branches dome-shaped, 7–15 µm in diameter, with the axial cells branching on alternate sides every 2 cells to originate determinate laterals and cutting off 6 pericentral cells (Fig. 151D, E), 2 larger lateral ones and 2 smaller ones on each side. The determinate laterals remain active for some time, cutting off the 6 pericentral cells and the lateral pericentral cells forming chains of 2–3, resulting in (3–) 5–6 large inner cells between the lateral veins; the determinate laterals fuse congenitally (Fig. 151B) to form the 4–6 mm broad main branches, with the apices of the determinate laterals forming the marginal fringe; trichoblasts occur as dense tufts on the end branches of the determinate laterals. Cortication generally 1 (–2) cells thick over the blades, heavier over the midrib. Cells probably uninucleate; rhodoplasts discoid.

Reproduction: Reproductive organs borne on branched clusters arising over the lateral veins on the branch surface.

Gametophytes dioecious. Procarps not observed. Carposporophytes with a basal fusion cell and branched gonimoblast with clavate terminal carposporangia 35–90 µm in diameter. Cystocarps (Fig. 151F) subspherical to slightly ovoid, 700–1500 µm in diameter; pericarp ostiolate, corticated. Spermatangial organs with 1–2 sterile basal cells, no sterile apical cells, ovoid to slightly tapering, 60–90 µm in diameter and 100–150 µm long.

Stichidia (Fig. 151G) in much-branched clusters 1–2 mm high, branches 100–180 µm in diameter with segments L/D 0.4–0.8, tetrasporangia single per segment, in short series maturing acropetally, 130–200 µm in diameter.

Type from Garden I., W. Aust.; lectotype in Herb. Harvey, TCD. (Harvey, Alg. Aust. Exsicc. 122a).

Selected specimens: 7 mile beach, N of Dongara, W. Aust., drift (Womersley, 17.ix.1979; AD, A51359). Port Denison, W. Aust., drift (Gordon, 8.xi.1968; AD, A33211). Point Peron, W. Aust., drift (Royce 932, 22.ii.1951; AD, A14180). Penguin I., W. Aust., drift (Wollaston, 3.ii.1957; AD, A22126). Eyre, W. Aust., drift (Woelkerling, 22.xi.1968; AD, A34232). Head of Great Australian Bight, S. Aust., drift (Womersley, 4.ii.1954; AD, A19222). W of Cape Adieu, S. Aust., 15 m deep (Edyvane, 21.vi.1994; AD, A64431). Point Sinclair, S. Aust., drift (Womersley, 7.ii.1954; AD, A19572). Elliston, S. Aust., drift (Woelkerling, 28.xii.1976; AD, A47866). Off Troubridge I., S. Aust., 23 m deep (Shepherd, 4.ii.1969; AD, A33528). Backstairs Passage, S. Aust. (no data; AD, A1318).

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

Distribution: N of Dongara, W Aust., to Backstairs Passage, S. Australia; doubtfully N Australia (Lewis 1984, p. 53).


AGARDH, J.G. (1863). Species Genera et Ordines Algarum. Vol. 2, Part 3, pp. 787–1291. (Gleerup: Lund.)

AGARDH, J.G. (1885). Till algernes systematik. VII. Florideae. Acta Univ. lund. 21, 1–120, Plate 1.

AGARDH, J.G. (1897). Analecta Algologica. Cont. IV. Acta Univ. lund. 33, 1–106, Plates 1, 2.

DE TONI, G.B. & FORTI, A. (1923). Alghe di Australia, Tasmania e Nouva Zelanda. Mem. R. Inst. Veneto Sci., Lett. Arti 29, 1–183, Plates 1–10.

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

FALKENBERG, P. (1901). Die Rhodomelaceen des Golfes von Neapel und der angrenzenden Meeres-abschnitte. Fauna und Flora des Golfes von Neapel. Monogr. 26. (Friedländer: Berlin.)

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. (1858). Phycologia Australica. Vol. 1, Plates 1–60. (Reeve: London.)

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.)

KÜTZING, F.T. (1864). Tabulae Phycologicae. Vol. 14. (Nordhausen.)

KYLIN, H. (1956). Die Gattungen der Rhodophyceen. (Gleerups: Lund.)

LEWIS, J.A. (1984). Checklist and bibliography of benthic marine macroalgae recorded from northern Australia. I. Rhodophyta. Dept. Defence, Materials Res. Lab., Melbourne, Vic. Report MRL-R-912.

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

LUCAS, A.H.S. (1909). Revised list of the Fucoideae and Florideae of Australia. Proc. Linn. Soc. N.S.W. 34, 9–60.

MAY, V. (1965). A census and key to the species of Rhodophyceae (red algae) recorded from Australia. Contr. N.S. W. Natl Herb. 3, 349–429.

SCHMITZ, F. & FALKENBERG, P. (1897). Rhodomelaceae. In Engler, A. & Prantl, K., Die natürlichen Pflanzenfamilien. T.1. Abt. 2, pp. 421–480. (Englemann: Leipzig.)

SHEPHERD, S.A. & SPRIGG, R.C. (1976). Substrate, sediments and subtidal ecology of Gulf St Vincent and Investigator Strait. In Twidale, C.R., Tyler, M.J. & Webb, B.P., Natural History of the Adelaide Region. (R. Soc. S. Aust.: Adelaide.)

SHEPHERD, S.A. & WOMERSLEY, H.B.S. (1981). The algal and seagrass ecology of Waterloo Bay, South Australia. Aquat. Bot. 11, 305–371.

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.)

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.

Illustration in Womersley Part IIIA, 2003: FIG. 151 A–G.

Figure 151 image

Figure 151   enlarge

Fig. 151. A–G. Dictyomenia sonderi (A, AD, A47866; B, AD, A33211; C, F, AD, A19572; D, E, G, AD, A64431). A. Habit. B. Indeterminate branch with marginal determinate laterals. C. Apex of indeterminate branch with determinate laterals. D. Transverse section of young branch with axial and 6 pericentral cells. E. Transverse section of older branch with thickened midrib. F. Cystocarps. G. Branches with tetrasporangia. H. Dictyomenia angusta (type, LD, 42315). Habit.

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