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Electronic Flora of South Australia Species Fact Sheet

Cystophora intermedia J. Agardh 1897: 102.

Phylum Phaeophyta – Order Fucales – Family Cystoseiraceae

Selected citations: Nizamuddin 1964c: 42–63. Womersley 1964: 69, figs 4,5, pl. 2.

Thallus (Pl. 7 fig. 2; Fig. 134A) dark brown, relatively slender, (10–) 20–70 (–85) cm long, with straight to slightly flexuous primary axes bearing relatively short secondary axes or laterals, with an overall elongate-tapering habit. Holdfast discoid-conical, 0.5–1.5 (–2.5) cm across, with one to several primary axes; epilithic in rough-water situations just below low tide. Primary axes oval in transverse section, 3–6 (–8) mm across and 2–4 mm thick, alternately distichously branched from their sides, usually denuded below with only slight branch residues; secondary axes terete to slightly ovoid in transverse section, pinnate, usually relatively slightly developed. Laterals 3–8 cm long, alternately to subdichotomously branched in one plane (becoming displaced); ramuli terete, slender, (1–) 2–5 cm long, 0.2–0.6 mm in diameter. Vesicles absent.

Reproduction: Thalli monoecious. Receptacles (Fig. 136C,D) simple, subfasciculate, terete to torulose, 0.5–1.5 (–2) cm long and 0.5–1 mm in diameter. Conceptacles adjacent, with scattered ostioles, bisexual; oogonia sessile, ovoid, 65–110 µm long and 40–65 µm in diameter; antheridia on branched paraphyses, elongate-ovoid, 16–24 µm long and 8–10 µm in diameter; simple, clavate, paraphyses present.

Type from Port Elliot, S. Aust. (Hussey); holotype in Herb. Agardh, LD, 1049.

Selected specimens: Point Sinclair, S. Aust., sublittoral fringe ( Womersley, 26.i.1951; ADU, A13604). St Francis I., Isles of St Francis, S. Aust., 2 m deep (Shepherd, 9.i.1971; ADU, A38120). Point 4 km N. of Cape Carnot, S. Aust., sublittoral fringe (Womersley, 9.i.1987; ADU, A57370-"Marine Algae of southern Australia" No. 275a). Wedge I., S. Aust., sublittoral fringe (Baldock, 29.xii.1963; ADU, A27260). Middle R., Kangaroo I., S. Aust., sublittoral fringe ( Womersley, 8.i.1946; ADU, A3462). Pennington Bay, Kangaroo I., S. Aust., sublittoral fringe ( Womersley, 20.viii.1963; ADU, A26800). Petrel Cove, Victor Harbor, S. Aust., sublittoral fringe (Womersley, 3.xii.1986; ADU, A57283-"Marine Algae of southern Australia" No. 275). Lawrence Rock, Portland, Vic., in rock pools (Beauglehole, 13.i.1954; ADU, A20515).

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

Distribution: From Point Sinclair, S. Aust. to Hogan I., Bass Str. (Saenger 1974, p. 75), on rocky coasts with extreme wave action.

Taxonomic notes: C. intermedia is a characteristic and usually dominant sub-littoral fringe species of rough-water coasts in South Australia between Point Sinclair and Victor Harbor; in south-eastern Australia it is replaced by Durvillaea and occurs only occasionally. The habit, ovoid axis (in transverse section) and terete-torulose receptacles are distinctive, though occasional broad-axis specimens approach C. moniliformis.


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

NIZAMUDDIN, M. (1964c). The anatomy and life history of Cystophora, Acrocarpia and Caulocystis (Fucales). Bot. Mar. 7, 42–63.

SAENGER, P. (1974). Natural history of the Hogan Group 2. Some marine algae from Hogan Island, Bass Strait, with an account of the marine zonation. Pap. Proc. R. Soc. Tasmania 107, 73–81.

WOMERSLEY, H.B.S. (1964). The morphology and taxonomy of Cystophora and related genera (Phaeophyta). Aust. J. Bot. 12, 53–110, Plates 1–16.

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: PLATE 7 fig. 2; FIGS 134A, 136C,D.

Plate 7 image

Plate 7   enlarge

PLATE 7 fig. 1. Scaberia agardhii in the sublittoral off Aldinga, S. Aust. (Photo: R. N. Baldock).
fig. 2. Cystophora intermedia in a low eulittoral pool at Vivonne Bay, Kangaroo I, S. Aust.

Figure 134 image

Figure 134   enlarge

Fig. 134. A. Cvstophora intermedia (ADU, A57283). B. Cystophora grevillei (ADU, A19252).

Figure 136 image

Figure 136   enlarge

Fig. 136. Receptacles of species of Cystophora. A. Cystophora platylobium (ADU, A26865). B. Cystophora moniliformis (ADU, A18823). C. Cystophora intermedia (ADU, A26800). D. Cystophora intermedia (ADU, A3462). E. Cystophora grevillei (ADU, A26752), axis with laterals and vesicles. F. Cystophora grevillei (ADU, A5713), receptacles. G. Cystophora xiphocarpa (ADU, A19808), axis with simple laterals.

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