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Chondria arcuata Hollenberg 1945: 447, figs 2–4.

Phylum Rhodophyta – Family Rhodomelaceae – Tribe Chondrieae

Selected citations: Abbott 1999: 357, fig. 103A. Abbott & Hollenberg 1976: 724, fig. 672, right. Adams 1994: 331, pl. 114, lower left. Dawson 1963: 442, p1. 167 figs 1–3. Gordon-Mills & Womersley 1987: 551, figs 24D, E, 27.

Thallus (Fig. 186A) red-brown, 3–7 cm high, with numerous slender, erect, branches arising from prostrate stolons; erect branches irregularly radially or largely unilaterally branched, upper parts frequently curved; lower parts of branches 250–500 µm in diameter, terminal parts 200–250 µm in diameter. Attachment of stolons by small rhizoidal haptera; epilithic or on debris, or epiphytic. Structure. Apices slightly depressed, pericentral cells 5 (Fig. 186B), becoming surrounded by a thin cortex, without rhizoid development and without cell wall thickenings; epidermal cells 20–35 µm in diameter and L/D (1.5–) 3–8. Cells with rhodoplasts discoid, chained in larger cells.

Reproduction: Gametophytes dioecious. Procarps not observed. Carposporophytes with a basal fusion cells and branched gonimoblast with clavate terminal carposporangia 30–45 µm in diameter. Cystocarps (Fig. 186C) ovoid, 600–900 µm in diameter, subsessile, without a spur; pericarp ostiolate, 2 cells thick, ecorticate. Spermatangial plates (Fig. 186D) discoid or slightly lobed, 300–600 µm across, with a single row (rarely 2 cells broad) of sterile marginal cells.

Tetrasporangia (Fig. 186E) near branch ends, on (1–) 3 pericentral cells per axial cell, 60–100 µm in diameter.

Type from Laguna Beach, Orange County, California, U.S.A. (Hollenberg, 29.x.1935); holotype in US, 61168.

Selected specimens: Port Noarlunga, S. Aust., on Sargassum, 2 m deep, outside of reef (Gordon-Mills, 26.iii.1987; AD, A56846). Apollo Bay, Vic., on pipeline in harbour (Kraft & Owen, 2.ix.1971; MELU, K3718a). Werribee, Port Philip Bay, Vic. (Brown, 20.iv.1983; AD, A53792). Gellibrand Light, Port Phillip Bay, Vic., 4–6 m deep (J. Lewis, 25.xi.1976; MELU, L1036 and 23.xii.1976; MELU, L1037), 1–2 m deep (J. Lewis, 27.i.1977; MELU, L1039) and 6–8 m deep (Kraft, 9.xii.1975; MELU, K5695).

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

Distribution: Port Noarlunga, S. Aust., to Port Phillip Bay, Victoria. Southern California and Pacific Mexico.

Taxonomic notes: The above specimens agree well with the Californian species but are slightly longer and more branched. Gordon-Mills & Womersley (1987, p. 552) suggested they may be adventives, being found mainly in harbours.


ABBOTT, I.A. & HOLLENBERG, G.J. (1976). Marine Algae of California. (Stanford Univ. Press: Stanford.)

ABBOTT, I.A. (1999). Marine Red Algae of the Hawaiian Islands. (Bishop Museum Press: Honolulu, Hawai'i.)

ADAMS, N.M. (1994). Seaweeds of New Zealand. (Cant. Univ. Press: Christchurch.)

DAWSON, E.Y. (1963). Marine red algae of Pacific Mexico. Part 8. Ceramiales: Dasyaceae, Rhodomelaceae. Nova Hedwigia 6, 401–481, Plates 126–171.

GORDON-MILLS, E.M. & WOMERSLEY, H.B.S. (1987). The genus Chondria C. Agardh (Rhodomelaceae, Rhodophyta) in southern Australia. Aust. J. Bot. 35, 477–565.

HOLLENBERG, G.J. (1945). New marine algae from southern California. 111. Am. J. Bot. 32, 447–451.

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. 186.

Figure 186 image

Figure 186   enlarge

Fig. 186. Chondria arcuata (A, AD, A53792; B, MELU, K5695; C, MELU, L1036; D, MELU, L1039; E, MELU, L1037). A. Habit. B. Transverse section of branch. C. Cystocarps. D. Spermatangial plates. E. Branches with tetrasporangia.

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