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Gonatogenia subulata J. Agardh 1896: 118.

Phylum Rhodophyta – Family Rhodomelaceae – Tribe Lophothalieae

Selected citations: Kylin 1956: 512, fig. 406. May 1965: 379. Shepherd & Womersley 1981: 367. Silva et al. 1996: 494.


Maschalostroma fastigiatum Falkenberg ex Schmitz & Falkenberg 1897: 435. De Toni 1903: 816.

Maschalostroma scoparium Schmitz ex Hauptfleisch 1897: 570 (nomen nudum). Falkenberg 1901: 233, pl. 22 figs 24, 25. Lucas 1929b: 51. Reinbold 1898: 50.

Alsidium ? comosum sensu J. Agardh 1890: 52, pl. 2 fig. 2.

Thallus (Fig. 122A) medium to dark red-brown, fading to yellow-brown, 20–60 (–100) cm high, cartilaginous, much branched irregularly with thickened main axes 1–3 mm in diameter below and long laterals (0.5–1 mm in diameter, becoming progressively shorter and slenderer, ultimate laterals usually 1–2 cm long and 100–200 µm in diameter; all branches terete, bare of trichoblasts below the apices. Holdfast discoid, 1–4 (–8) mm across; epilithic. Structure monopodial, with subapical cells cutting off 5–7 pericentral cells (Fig. 122B), soon becoming corticated, pericentral cells becoming separated by smaller irregular cells and indistinct in older branches (Fig. 122C). Trichoblasts rhodoplastic, only present near apices, simple, with 3–7 small, isodiametric, basal cells (Fig. 122D), then increasing rapidly to (15–) 20–35 (–50) µm in diameter and L/D 3–8 (–12). Cells multinucleate; rhodoplasts discoid.

Reproduction: Reproductive organs borne on small branch systems (Fig. 122F) in axils of upper laterals.

Gametophytes dioecious. Procarps developing on a small basal cell of the trichoblasts which then become polysiphonous. Carposporophytes with a large basal fusion cell producing erect, clavate, terminal carposporangia. Cystocarps (Fig. 122E) ovoid, becoming globular, 1–2 mm in diameter, short-stalked, without a neck; pericarp ostiolate, thick, with outer small cortical cells. Spermatangial organs 150–250 µm long and 35–45 µm in diameter.

Stichidia (Fig. 122F, G) in axillary, basally branched (or from the primary branch) tufts 1–2 mm long, fertile branches 600–1000 µm long and 150–350 µm in diameter, with trichoblasts on the upper segments, tetrasporangia in decussate pairs, 100–180 µm in diameter.

Lectotype from Port Phillip (Heads) or Western Port, Vic. (Wilson, 7.iv.1893); in Herb. Agardh, LD, 42240. Selection of a lectotype is uncertain but should be based on a specimen labelled "Port Phillip Heads or Western Port" and labelled "TYPUS" in LD. J. Agardh referred to several locations in his protologue, but not to Western Port.

Selected specimens: "The Hotspot", W of Flinders I., S. Aust., 32 m deep (Branden, 21.vi.1988; AD, A59295). El liston, S. Aust., 11 m deep in bay (Shepherd, 14.v.1971; AD, A38640). Off Troubridge Light (Edithburg), S. Aust., 18 m deep (Shepherd, 4.ii.1969; AD, A33567). Victor Harbor, S. Aust, drift (Womersley, 22.iv.1951; AD, A15505). Cape Jervis, S. Aust., 15 m deep (Shepherd, 5.xii.1985; AD, A56953). Pennington Bay, Kangaroo I., S. Aust., drift (Womersley, 22.viii.1954; AD, A19767). Ironstone Point, E of Penneshaw, Kangaroo I., S. Aust., 6 m deep (Lavers, 13.iii.1996; AD, A64815) and 10–15 m deep (Lavers, 12.i.1997; AD, A67006). Kingston, S. Aust., drift (Womersley, 9.viii.1961; AD, A24870). Robe, S. Aust., drift (Womersley, 23.ix.1986; AD, A57204). Double Corner Beach, Portland, Vic., drift (Beauglehole, 22.vi.1952; AD, A21536). Point Leo, Western Port, Vic., drift (Wollaston, 19.viii.1956; AD, A20576). Walkerville, Vic., drift (Sinkora A2345, 5.iii.1977; AD, A48389).

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

Distribution: Flinders I., S. Aust. to Walkerville, Victoria. Not known in Western Australia as inferred by Silva et al. 1996, p. 494.

Taxonomic notes: Gonatogenia subulata is characterised by its habit, denuded of trichoblasts except close to apices, by the row of 3–7 small cells at the base of the simple trichoblasts, and by the occurrence of reproductive organs on branched axillary systems. The number of pericentral cells varies from 5 to usually 6 or 7, which especially in dried specimens are often not clear.

In describing G. subulata, J. Agardh (1896, p. 118) based it on his mis-interpretation (as f. denudata according to Schmitz & Falkenberg 1897, p. 435) of Alsidium comosum Harvey (now Holotrichia comosa) and he referred to f. comosa and f. subulifera. Schmitz in Schmitz & Falkenberg (1897, p. 435) described Maschalostroma fastigiata Falkenberg, based on the same J. Agardh mis-interpretation, and Falkenberg (1901, p. 233) used the name M. scoparium for the same species. Kylin (1956, p. 512) realised these names applied to the one taxon, and the forms appear to be only growth states.


AGARDH, J.G. (1890). Till algernes systematik. Acta Univ. lund. 26(3), 1–125, Plates 1–3.

AGARDH, J.G. (1896). Analecta Algologica. Cont. III. Acta Univ. lund. 32, 1–140, Plate 1.

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.)

HAUPTFLEISCH, P. (1897). Anhang. In Engler, A. & Prantl, K. Die natürlichen Pflanzenfamilien. 1 Th. 2 Abteil. Pp. 545–570. (Engelmann: Leipzig.)

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

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

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.

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

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. & 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.)

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

Author: H.B.S. Womersley & M.J. Parsons

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. 122.

Figure 122 image

Figure 122   enlarge

Fig. 122. Gonatogenia subulata (A, D, E, AD, A38640; B, AD, A64815; C, AD, A67006; F, G, AD, A59295). A. Habit. B. Transverse section of young branch. C. Transverse section of older branch. D. Young branch with simple trichoblasts with minute basal cells. E. Branch with young cystocarps. F. Axillary cluster of stichidia. G. Stichidia with decussate pairs of tetrasporangia.

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