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Electronic Flora of South Australia Species Fact Sheet

Arthrocardia flabellata (Kützing) Manza ssp. australica Womersley & Johansen 1988: 43, figs 2C, D, 3D–L, 4.

Phylum Rhodophyta – Class Florideophyceae – Order Corallinales – Family Corallinaceae – Subfamily Corallinoideae – Tribe Corallineae

Thallus (Fig. 134A, B) pale grey-red, slender, 2–4 (–6) cm high, with fronds in small groups with axes sparsely pinnate (Fig. 134B) from about half the axial intergenicula, largely complanately branched. Intergenicula terete below and 300–500 µm in diameter, above compressed with linear margins and slight to conspicuous obtuse to pointed lobes, 1.5–3.5 mm long and 0.7–1.4 mm broad, L/W 2–4. Holdfast crustose, thick, 2–10 mm across; epilithic. Structure. Intergenicula (Fig. 134C) with 20–40 (–50) tiers of medullary cells, each tier 50–75 µm long, cell-fusions numerous, cortex of assurgent filaments 5–10 cells long, 5–9 µm in diameter and L/D 3–6, with single, short, epithallial cells. Genicula 120–250 µm long. Rhodoplasts discoid to laminate.

Reproduction: Gametangial thalli dioecious. Carpogonial conceptacles originating at apices of short lateral branchlets. Carposporangial conceptacles (Fig. 134D) with branchlets on one or both sides, chamber 300–520 µm in diameter, fusion cell 220–310 µm across and 8–10 µm thick, carposporangia in filaments of 3–4 cells (Fig. 134E), 55–80 µm in diameter. Male conceptacles beaked, with branchlets or processes on each side, chambers 375–650 µm in diameter, 400–550 µm high, canal 800–900 µm long.

Tetrasporangial conceptacles (Fig. 134F) only slightly swollen, surmounted by two branches, chambers 500–750 µm in diameter, 600–700 µm high; tetrasporangia 140–280 µm long, 40–80 µm in diameter.

Type from Nora Creina, S. Aust., upper sublittoral in large shaded pool (Johansen 81–9–49, 16.xi.1981, carposporangial, male); holotype in AD, A52790.

Selected specimens: Smooth Pool, near Streaky Bay, S. Aust. (Johansen 81–10–21d, 28.x.1981, tetrasporangial). West Bay, Kangaroo I., S. Aust., near low tide (Woelkerling, 21.ii.1979; LTB, 11612; AD, A57529). Point Gillian, West I., S. Aust., 0.5–1 m deep (Shepherd, 27.v.1967; AD, A31943). Robe, S. Aust., sublittoral (Jones & Johansen 81–9–24, 4.ix.1981, carposporangial; AD, A52792). Nora Creina, S. Aust., in large shaded pool (Johansen 81–9–25, 5.ix.1981, carposporangial; AD, A52791 and 81–9–43, 15.ix.1981; CUW, 8548). 400 m off Cape Buffon, S. Aust., 5 m deep (Collings, 25.i.1991; AD, A61241). Cape Northumberland, S. Aust., in heavily shaded rear-reef pool (Womersley, 24.ii.1992; AD, A61609 -"Marine Algae of southern Australia" No. 363). Point Lonsdale, Vic., upper sublittoral (Johansen 81–8–16, 31.viii.1981, tetrasporangial). Walkerville, Vic., low eulittoral (Pope & Bennett, 19.v.1949; AD, Al2218). Currie R. mouth, Tas., upper sublittoral (Womersley, 28.i.1949; AD, A10326). Stapleton Point, Prosser Bay, Tas., 0–3 m deep (Shepherd, 10.ii.1970; AD, A35686). Lady Bay, Southport, Tas., 7 m deep (Brown & Kenchington, 14.x.1986; AD, A57693, carposporangial and male).

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

Distribution: From Streaky Bay, S. Aust., to Walkerville, Vic., and around Tasmania, in shallow water but usually in shaded situations.

Taxonomic notes: Arthrocardia flabellata is a South African species, from which ssp. australica differs in being slenderer and with conceptacles produced in single intergenicula which rarely branch to produce other fertile intergenicula (Womersley & Johansen 1988, p. 45).

The southern Australian taxon is not common, usually found in shaded low-level pools to a few metres deep.


WOMERSLEY, H.B.S. & JOHANSEN, H.W. (1988). The genus A rthrocardia (Corallinaceae: Rhodophyta) in southern Australia. Trans. R. Soc. S. Aust. 112, 39–49.

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

Author: H.B.S. Womersley & H.W. Johansen

Publication: Womersley, H.B.S. (28 June, 1996)
The Marine Benthic Flora of Southern Australia
Rhodophyta. Part IIIB. Gracilarialse, Rhodymeniales, Corallinales and Bonnemaisoniales
Reproduced with permission from The Marine Benthic Flora of Southern Australia Part IIIB 1996, by H.B.S. Womersley. Australian Biological Resources Study, Canberra. Copyright Commonwealth of Australia.

Illustration in Womersley Part IIIA, 1996: FIG. 134.

Figure 134 image

Figure 134   enlarge

Fig. 134. Arthrocardia flabellata ssp. australica (A, AD, 61609; B, AD, A52791; C, AD, A52790; D, E, Johansen 81-9-43, CUW8548; F, AD, A61241). A. Habit. B. Branches with conceptacles. C. Longitudinal section of a geniculum and part intergeniculum. D. Longitudinal section of a segment with a carposporangial conceptacle. E. Carposporangial conceptacle with thin, broad, fusion cell and peripheral filaments with carposporangia. F. Longitudinal section of a bisporangial conceptacle. [D, E, Photos H.W.J.]

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