Electronic Flora of South Australia Species Fact Sheet
Phylum Rhodophyta – Class Florideophyceae – Order Gigartinales – Family Cystocloniaceae
Selected citations: De Toni 1900: 489. Kylin 1956: 300.
Thallus (Fig. 151D) medium to dark red-brown to brown, 4–12 cm high, much branched furcately to irregularly on all sides, branches filiform, 200–250 µm in diameter below, decreasing gradually to 100–150 µm near the apices. Holdfast fibrous, entangled; epilithic, possibly epiphytic. Structure uniaxial, apical cell protuberant, axial filament clear in most branches (Fig. 152I); medulla pseudoparenchymatous, inner cells ovoid, 30–70 µm in diameter, with the outer cells 6–20 µm across, cutting off a few small ovoid to angular rosette cells (Fig. 151E); rhodoplasts discoid to elongate, becoming ribbon shaped and branched, few to several per cell.
Reproduction: Sexual thalli apparently dioecious; procarps unknown. Cystocarps protuberant, globose and basally constricted, 450–750 µm in diameter, borne on upper branches, with the carposporophyte (Fig. 151F) having a small-celled basal tissue bearing branched gonimoblast filaments with terminal chains of ovoid carposporangia 8–15 µm in diameter; pericarp well developed, non-ostiolate. Spermatangia unknown.
Tetrasporangia (Fig. 152I) scattered in the cortex, laterally pit-connected to inner cortical cells, ovoid, 28–38 µm long and 15–25 µm in diameter, zonately divided.
Type from Port Phillip Heads, Vic. (Wilson); lectotype Wilson '73', 2.ii.1886; in Herb. Agardh, LD, 27133.
Distribution: Only known from Port Phillip Heads, Vic. (Wilson specimens in LD and MEL) and Port Noarlunga, S. Aust., lowest eulittoral on shore rocks near jetty (Ricci, 24.i.1993; AD, A61795 and Womersley & Ricci, 8.ii.1993; AD, A61851).
MEL has four sheets of Wilson specimens, from Port Phillip Heads, Vic., all collected prior to Agardh's description; Wilson's '73', dated 31.i.83 (MEL, 694643) and 26.i.86 (MEL, 694642), and un-numbered ones dated 6.ii.89 (MEL, 694644) and 1.iv.1891 (MEL, 694645). A duplicate of MEL, 694644 is in AD, A8305. All these are not obviously fertile, but J. Agardh apparently had a cystocarpic specimen. J. Agardh used the name Heringia ceramioides on most of the sheets.
Taxonomic notes: The recent collections from Port Noarlunga agree well with the Wilson specimens and are fertile, with cystocarpic and tetrasporangial plants. Details of the female reproduction and carposporophyte development merit further study, but Erythronaema appears well placed in the Cystocloniaceae.
AGARDH, J.G. (1892). Analecta Algologica. Acta Univ. lund. 28, 1–182, Plates 1–3.
DE TONI, G.B. (1900). Sylloge Algarum omnium hucusque Cognitarum. Vol. 4. Florideae. Sect. 2, pp. 387–776. (Padua.)
KYLIN, H. (1956). Die Gattungen der Rhodophyceen. (Gleerups: Lund.)
The Marine Benthic Flora of Southern Australia Part IIIA complete list of references.
Womersley, H.B.S. (14 January, 1994)
The Marine Benthic Flora of Southern Australia
Rhodophyta. Part IIIA, Bangiophyceae and Florideophyceae (to Gigartinales)
Reproduced with permission from The Marine Benthic Flora of Southern Australia Part IIIA 1994, by H.B.S. Womersley. Australian Biological Resources Study, Canberra. Copyright Commonwealth of Australia.
Illustrations in Womersley Part IIIA, 1994: FIG. 151 D–F, 152 I.
Figure 151 enlarge
Fig. 151. A–C. Austroclonium charoides (A, AD, A27117; B, AD, A27480; C, AD, A41219). A. Habit. B. Surface view of slight rosettes. C. Carposporophyte with fusion cell, chains of carposporangia, and lax filamentous involucre. D–F. Erythronaema ceramioides (D, E, AD, A8305; F, AD, A61795). D. Habit. E. Surface view of branch with rosettes. F, Section of cystocarp with erect, spreading carposporophyte with chains of carposporangia. [C as in MM-Thein & Womersley 1976.]
Figure 152 enlarge
Fig. 152. A–H. Austroclonium charoides (A–D, H, AD, A27480; E, F, AD, A41219; G, AD, A38307). A. Branch apex showing axial filament and periaxial cells. B. Transverse section of branch with axial filament, rhizoidal medulla and single-layered cortex. C. Surface view of rosettes. D. Longitudinal view of tendril branch with modified tip and lower spinous outgrowths. E. Longitudinal section of cortex with a carpogonial branch. F. Longitudinal section showing fusion of carpogonium and auxiliary cell, darkly staining cortical cells with outer cells forming the young pericarp, and young involucral filaments. G. Section of cortex with spermatangia. H. Longitudinal section of branch with tetrasporangia. I. Erythronaema ceramioides (AD, A61795). Longitudinal section of branch with tetrasporangia. [A–H after Min-Thein & Womersley 1976.]
State Herbarium of South Australia