Electronic Flora of South Australia Species Fact Sheet
Phylum Chlorophyta – Order Cladophorales – Family Cladophoraceae
Cl. gracilis (Griffiths ex Mackay) Kützing. Womersley 1956: 359.
Cl. thoreana Kützing. Tate 1882: 93. Womersley 1956: 361.
Thallus (Fig. 69A) light to medium green, to 25 cm high, forming densely branched erect tufts of one to several pseudodichotomous main axes attached by rhizoids from cells in the basal region (Fig. 70B); these axes bear branch systems composed of filaments which are lined with unilateral rows of appressed branchlets but often with long series of unbranched cells throughout the thallus; main axes distinctly tapering towards the apical cells (Fig. 70A). Growth mainly intercalary, resulting in a feebly acropetal to irregular organisation, the main filaments lined in parts with rows of branches and branchlets (Fig. 70A), the younger ones intercalated between the older (longer) ones; parent cells with 1–2 (–3) laterals at an acute angle, basal cross wall of laterals oblique, soon becoming horizontal.
Apical cells (Fig. 70A) more or less tapering, 30–55 µm in diameter and L/B 3–10; ultimate branch cells 30–95 µm in diameter and L/B 2.5–9; lower thallus cells 130–170 µm in maximum diameter and L/B 1.5–6.5; ratio of lower cell to apical cell diameters 2.5–4; cell walls 2–4 µm thick in apical cells, 4–10 µm thick in mid cells and 15–20 µm thick below.
Reproduction: Reproduction (van den Hoek 1963, p. 79) by biflagellate gametes and quadriflagellate (sometimes biflagellate) zoospores formed in chains of short, swollen terminal zooidangia.
Type from England; in OXF (see van den Hoek 1963, p. 77),
Selected specimens: Entrance to Kellidie Bay, Coffin Bay, S. Aust., very low eulittoral (Womersley, 22.viii.1967; ADU, A31817). Kirk Point, Port Phillip, Vic., shallow sublittoral (van den Hoek 81/4, 30.viii.1981; ADU, A52687). Port Effingham, Tamar Est., Tas. (Perrin & Lucas, Jan. 1930; HO, 44863–4). Stewarts Bay, Port Arthur, Tas., 3–7 m deep (Cribb, 13.vi.1951; ADU, A21041). Southport, Tas., on Hormosira (Cribb 44.11, 21.iii.1950; HO, 44888).
Distribution: Widely distributed along cool to warm temperate N. Atlantic, N. Pacific and Southern Hemisphere shores (van den Hoek 1982, p. 96).
In southern Australia from Coffin Bay, S. Aust. to Port Phillip, Vic. and around Tasmania, usually in sheltered bays.
Taxonomic notes: Cl. sericea is similar to Cl. crinalis from which it differs by not forming dense tufts of many axes, by having tapering instead of cylindrical apical cells (with slightly tapering tips), and by the more pronounced increase in diameter from apical cells to main axes. The branched habit with laterals of different ages intermixed is quite characteristic.
TATE, R. (1882). Additions to the flora of South Australia. Trans. R. Soc. S. Aust. 5, 82–93.
VAN DEN HOEK, C. (1963). Revision of the European species of Cladophora. (Brill: Leiden.)
VAN DEN HOEK, C. (1982). A taxonomic revision of the American species of Cladophora (Chlorophyceae) in the North Atlantic Ocean and their geographic distribution. Verh. k. Ned. Akad. Wet. Afd. Natuurkd. Tweede Reeks, Part 78.
WOMERSLEY, H.B.S. (1956). A critical survey of the marine algae of southern Australia. I. Chlorophyta. Aust. J. mar. freshw. Res. 7, 343–383.
The Marine Benthic Flora of Southern Australia Part I complete list of references.
Womersley, H.B.S. (31 May, 1984)
The Marine Benthic Flora of Southern Australia
©Board of the Botanic Gardens and State Herbarium, Government of South Australia
Illustrations in Womersley Part I, 1984: FIGS 69A, 70A,B.
Figure 69 enlarge
Fig. 69, A. Cladophora sericea (ADU, A31817). B. Cladophora vadorum (ADU. A32744). C,D. Wittrockiella salina, C. (ADU, A53315), D. (ADU, A53084).
Figure 70 enlarge
Fig. 70. A,B. Cladophora sericea (ADU, A52687). A. Upper branch system. B. Base of thallus with rhizoids. C. Cladophora vadorum (ADU, A32744). Upper branch system.
State Herbarium of South Australia