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Electronic Flora of South Australia Species Fact Sheet
Phylum Rhodophyta – Family Rhodomelaceae – Tribe Chondrieae
Selected citations: Millar & Kraft 1993: 51. Silva et al. 1996: 479.
Thallus (Fig. 185A) brown-red, fading to yellow-red, 2–10 cm high, very slender, much branched radially for 3–4 orders, branches spreading and often entangled, terete; lower branches or axes 500–750 µm in diameter, grading to lesser branchlets 150–200 (–250) µm in diameter. Holdfast discoid, 200–500 µm across; epiphytic on Zostera or Gracilaria, or unattached, or epilithic, in sheltered estuarine conditions. Structure. Apices pointed, occasionally slightly rounded, with an apical filament 10–12 cells long, cortex becoming a few cells broad; epidermal cells 15–25 µm in diameter and L/D 5–12; rhizoids and cell wall thickenings absent. Trichoblasts profuse at and near branch apices, 1–2 mm long. Lateral branches arising from basal cells of trichoblasts. Cells multinucleate; rhodoplasts discoid to elongate.
Reproduction: Gametophytes dioecious. Procarps on a lower cell of trichoblasts. Carposporophytes with a branched, basal fusion cell and short branched gonimoblast with clavate terminal carposporangia 30–55 µm in diameter. Cystocarps (Fig. 185B) ovoid, short-stalked, 400–600 µm in diameter, with a short basal spur; pericarp ostiolate, with 10–14 erect filaments, 2 cells thick, ecorticate. Spermatangial plates (Fig. 185C) formed as a basal branch on trichoblasts, irregularly discoid to obcordate, 200–350 µm across, with sterile terminal cells to the trichoblast branches, but otherwise spermatangia formed by marginal cells.
Tetrasporangia (Fig. 185D) in swollen lesser branches 200–250 µm in diameter, on 2–3 pericentral cells per axial cell, 100–120 µm in diameter, with conspicuous cover cells.
Type from Onkaparinga Estuary, S. Aust., on Zostera muelleri (Gordon-Mills & Robertson, 9.ii.1984-"Marine Algae of southern Australia" No. 310); holotype and isotypes in AD, A53797, isotypes in the above distributed set.
Selected specimens: Leschenault Inlet, SW W. Aust., (Walker, 23.iv.1985; AD, A56818). Onkaparinga Est., S. Aust., 10 km downstream from Noarlunga (Thomas, 27.i.1977; AD, A47883), and on Gracilaria near mouth (Gordon-Mills, 10.xii.1981; AD, A52062). American R. inlet, Kangaroo I., S. Aust., 2–4 m deep near Muston (Womersley, 22.viii.1963; AD, A26871). Glenelg R. mouth, Vic., on rock (Beauglehole, 26.i.1952; AD, A21544). Mallacoota, Vic., floating in estuary lagoon (Womersley, 12.xi.1982; AD, A53693). Port Stevens, N.S.W. (Wheeler & King, 14.ix.1983; UNSW, 15067; AD, A55705).
Distribution: Leschenault Inlet, W. Aust., to Port Stevens, N.S.W.
Taxonomic notes: Chondria angustissima is the most slender species of the genus in southern Australia, confined to sheltered estuarine conditions.
References:
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.
MILLAR, A.J.K. & KRAFT, G.T. (1993). Catalogue of marine and freshwater Red Algae (Rhodophyta) of New South Wales, including Lord Howe Island, South-western Pacific. Aust. Syst. Bot. 6, 1–90.
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.
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. 185.
Figure 185 enlarge
Fig. 185. Chondria angustissima (A, C, AD, A53797; B, D, AD, A52062). A. Habit, on Zostera. B. Cystocarp. C. Branch with spermatangial plates. D. Branches with tetrasporangia.
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