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Electronic Flora of South Australia Species Fact Sheet
Phylum Rhodophyta – Family Delesseriaceae
Thallus (Fig. 27A) rose-red, tufted, 5–12 cm high, much branched laterally from the margins and more or less complanately, branches 2–5 mm broad, tapering slightly to 2–3 mm broad near the apices, margin with small, spinous, irregularly spaced laterals each with an apical cell; veins absent; blades monostromatic. Holdfast unknown; probably epilithic. Structure. Growth from small but distinct apical cells (Fig. 27B, C) which segment with a curved to straight wall, the derivative laterally elongate cell then dividing transversely to give 2–4 cuboidal cells; no axial filament is apparent and the lateral cells do not form distinct rows (Fig. 27B), but intercalary divisions occur in the immediate and lateral derivatives. Mature cells angular, often in longitudinal lines, 30–60 µm across and L/D 1–2; marginal cells isodiametric, 15–25 µm across. Cells multinucleate; rhodoplasts discoid, becoming chained.
Reproduction: Gametophytes probably dioecious. Procarps (Fig. 41A) scattered, each with a 2-celled cover-cell group, a 4-celled carpogonial branch and a 3-celled sterile group, the carpogonial branch lying between the 2 groups (Fig. 27D). Carposporophytes with a basal fusion cell and moderately branched gonimoblast with large, clavate to ovoid, terminal carposporangia (Fig. 27E, F) 45–110 µm in diameter. Cystocarps scattered, 0.5–1 mm across, hemispherical; pericarp ostiolate, 2–3 cells thick, cells relatively large, 30–50 µm across. Spermatangial thalli unknown.
Tetrasporangial sori (Fig. 27G) scattered, mostly just within the margins or near the base of laterals, ovate, 350–650 µm across, with tetrasporangia cut off from the primary cells and lying between them more or less in one layer of mixed ages, covered on each side by an adherent layer of cortical cells; tetrasporangia subspherical, (50–) 80–150 µm in diameter.
Type from American R. inlet, Kangaroo I., S. Aust., drift at jetty (Womersley, 31.x.1966); holotype in AD, A30838.
Selected specimens: Muston, American R. inlet, Kangaroo I., S. Aust., upper sublittoral (Womersley, 2.xi.1947; AD, A6129, 29.xii.1949; AD, A12912, 27.viii.1950; AD, A15370, 27.viii.1950; AD, A15374, and 22.viii.1963; AD, A26977).
Distribution: Only known from American R. inlet, Kangaroo I., S. Australia; not collected recently.
Taxonomic notes: Haraldia australica differs from the type species and H. tenuis in habit, being more irregularly branched.
References: The Marine Benthic Flora of Southern Australia Part IIID
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.
Illustrations in Womersley Part IIIA, 2003: FIGS 27, 41A.
Figure 27 enlarge
Fig. 27. Haraldia australica (A–D, G, AD, A30838; E, F, AD, A15370). A. Habit. B. Branch apex with apical cells. C. Apical cells and segmentation. D. Procarp with a 3-celled sterile cell group (on left), a 4-celled carpogonial branch and a 2-celled cover cell group (on right). E. Cystocarp with large terminal carposporangia, from above. F. Cystocarp, sectional view. G. Tetrasporangial sorus.
Figure 41 enlarge
Fig. 41. Procarps. A. Haraldia australica (AD, A30838). B, C. Nitospinosa pristoidea (AD, A68077; AD, A68122 resp.). D, E. Robea costata (AD, A68095; AD, A64063 resp.).
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