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Electronic Flora of South Australia Species Fact Sheet

Gulsonia annulata Harvey 1855b: 334; 1859b: 320, pl. 193A; 1863, synop.: xlvii.

Phylum Rhodophyta – Order Ceramiales – Family Ceramiaceae – Tribe Crouanieae

Selected citations: J. Agardh 1876: 88; 1894a: 122, pl. 2 fig. 13; 1897: 56. Bastow 1899: pl. 2 fig. 60. De Toni 1897: 66; 1924: 151. Feldmann-Mazoyer 1940: 279. Kützing 1866: 23, pl. 66c–e. Kylin 1956: 372. Lucas 1909: 21; 1929a: 15. May 1965: 375. Schmitz & Hauptfleisch 1897: 331. Sonder 1881: 12. Wollaston 1968: 277, fig. 13A. Wollaston & Womersley 1959: 55, figs 1–4. Womersley 1948: 161; 1950: 178.

Thallus (Fig. 23F) medium to dark red-brown, 5–20 (–30) cm high, very mucilaginous, much branched irregularly with one to a few main axes and long lateral branches with conspicuous annulations (Fig. 24A) due to the whorls of whorl-branchlets; branches terete, 1–2.5 mm in diameter below, tapering to 0.2–0.5 mm in diameter shortly below apices. Holdfast discoid, 1–5 mm across; epilithic. Structure. Apical cells 10–12 µm in diameter and L/D 0.5–1, increasing shortly below apices to 20–30 µm in diameter and L/D 1.2–1.5, and in lower thallus to 250–500 µm in diameter and L/D 1.2–1.5. Lateral branches (Fig. 24B) originating from the basal cells of whorl-branchlets, becoming 16–20 cells long before initiating whorl-branchlets. Axial cells each with 4 whorl-branchlets of equal size (Fig. 24F), 350–750 µm long, forming annulations with the axial cells (or cortication) visible between them except near branch apices; whorl-branchlets branched 5–7 times di- or trichotomously, basal cells 35–75 µm in diameter and L/D 1–1.5, tapering to terminal cells 8–12 µm in diameter and L/D 1.2–2, often with terminal hairs; pyriform gland-cells (Fig. 24G) occur on mid cells of the whorl-branchlets, often with crystal-like inclusions. Mature axes are corticated by rhizoids from the basal cells of whorl-branchlets, becoming dense below. Cells uninucleate; rhodoplasts elongate, ribbon like in older cells.

Reproduction: Gametophytes dioecious. Procarps (Fig. 24C) single or opposite below the apices of short lateral branches which cease further growth; the supporting cell bears a curved 4-celled carpogonial branch, and post-fertilization a connecting cell is cut off and fuses with the auxiliary cell which forms a lower foot cell and an upper cell which develops successive rounded gonimolobes (Fig. 24D) 90–140 µm across of ovoid carposporangia 20–25 µm in diameter; lower whorl-branchlets surround the carposporophyte (Fig. 24D). Spermatangia (Fig. 24E) are cut off terminally on outer cells of the whorl-branchlets, ovoid or constricted, 3.5–5 µm in diameter.

Tetrasporangia (Fig. 24G) occur on third-order cells of the whorl-branchlets, sessile, subspherical, 60–120 in diameter.

Type from Phillip I., Western Port, Vic. (Harvey); lectotype in MEL, 5] 7745. No type specimen could be located in TCD (1975), but the MEL specimen is labelled "396. Phillip I., Western Port, rare, W.H.H. Gulsonia annulata H. nov. gen."

Selected specimens: Hopetoun, W. Aust., 3–4 m deep (Kraft 6997 & Ricker, 16.viii.1979; AD, A50716). Eucla, W. Aust., drift (Womersley, 2.ii.1954; AD, A19359). St Francis I., Isles of St Francis, S. Aust., 19–20 m deep (Shepherd, 6.i.1970; AD, A37961). Fishery Bay, Port Lincoln, S. Aust., drift (Womersley, 21.ii.1959; AD, A22472). Tapley Shoal, S. Aust., 16 m deep (Mitchell, May 1961; AD, A28096). Aldinga, S. Aust., drift (Womersley, 31.xii.1967; AD, A32196). Victor Harbor, S. Aust., drift (Parsons, 10.i.1970; AD, A35028). Vivonne Bay, Kangaroo I., S. Aust., drift (Womersley, 2.i.1949; AD, A10613). Pennington Bay, Kangaroo I., S. Aust., drift (Wollaston, 11.ii.1956; AD, A20059 - "Marine Algae of southern Australia" No. 97). Cable Hut reef, E of Penneshaw, Kangaroo I., S. Aust., 15–21 m deep (Lavers, 14.ii.1996; AD, A64838). Low Head, Tas. (Perrin 785, Feb. 1967; BM). Currie R., Tas. (Perrin & Lucas, Jan. 1936; AD, A49641). Spring Beach, Orford, Tas., 3–8 m deep (Blackman 78–107, 1978; AD, A58565).

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

Distribution: Hopetoun, W. Aust., to Phillip I., Vic., and N and E Tasmania.

Taxonomic notes: G. annulata is a deep-water species known mainly from the drift, distinguished by its extremely mucilaginous thallus with prominent annular rings of the whorl-branchlets, though these are best seen in the mid thallus of most plants.


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

AGARDH, J.G. (1894a). Analecta Algologica. Cont. I. Acta Univ. lund. 29, 1–144, Plates 1, 2.

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

BASTOW, R.A. (1899). Key to tribes and genera of the Florideae. J. Proc. R. Soc. N.S.W. 33, 45–47, Plates 1, 2.

DE TONI, G.B. (1897). Sylloge Algarum omnium hucusque Cognitarum. Vol. 4. Florideae. Sect. 1, pp. 1–388. (Padua.)

DE TONI, G.B. (1924). Sylloge Algarum omnium hucusque Cognitarum. Vol. 6. Florideae. (Padua.)

HARVEY, W.H. (1855b). Short characters of some new genera and species of algae discovered on the coast of the Colony of Victoria, Australia. Ann. Mag. Nat. Hist. 15 (ser. 2), 332–336.

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.)

KÜTZING, F.T. (1866). Tabulae Phycologicae. Vol. 16. (Nordhausen.)

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

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

LUCAS, A.H.S. (1929a). The marine algae of Tasmania. Pap. Proc. R. Soc. Tasm. 1928, 6–27.

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

SCHMITZ, F. & HAUPTFLEISCH, P. (1897). Ceramiaceae. In Engler, A. & Prantl, K., Die natarlichen Pflanzenfamilien, Vol. 1, Part 2, pp. 481–504. (Leipzig.)

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

WOLLASTON, E.M. & WOMERSLEY, H.B.S. (1959). Structure and reproduction of Gulsonia annulata Harvey (Rhodophyta). Pacif. Sci. 13, 55–62.

WOLLASTON, E.M. (1968).Morphology and taxonomy of southern Australian genera of Crouanieae Schmitz (Ceramiaceae, Rhodophyta). Aust. J. Bot. 16, 217–417.

WOMERSLEY, H.B.S. (1948). The marine algae of Kangaroo Island. II. The Pennington Bay Region. Trans. R. Soc. S. Aust. 72, 143–166, Plates 10–15.

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 IIIC complete list of references.

Author: E.M. Wollaston & 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: FIG. 23F, 24.

Figure 23 image

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Fig. 23. A–E. Ptilocladia crouanioides (A, AD, A48322; B, AD, A38377; C, AD, A37692; D, E, AD, A62191). A. Habit. B. Young branches. C. Young branch with gland cells on whorl-branchlets. D. Young branches with carposporophytes. E. Older corticated axis with young lateral bearing a carposporophyte. F. Gulsonia annulata (AD, A20059). Habit.

Figure 24 image

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Fig. 24. Gulsonia annulata (AD, A20059). A. Branches with carposporophytes. B. Development of a lateral from the basal cell of a whorl-branchlet. C. A young lateral with 3 carpogonial branches. D. Carposporophyte with apical and lateral gonimolobes. E. A whorl-branchlet with hairs and terminal spermatangia. F. Transverse section of a branch with tetrasporangia. G. A whorl-branchlet with tetrasporangia and a short lateral branch. (A as in Wollaston 1968, courtesy of Aust. J. Bot; B–G after Wollaston & Womersley 1959, by courtesy of Pacific Science, Univ. Hawai'i Press.)

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