Electronic Flora of South Australia Species Fact Sheet
Phylum Phaeophyta – Order Dictyotales – Family Dictyotaceae – Tribe Zonarieae
Selected citations: Allender & Kraft 1983: 81, figs 4G,H, 5A,B.
Gymnosorus variegatus (Lamouroux) J. Agardh 1894a: 11.
Pocockiella variegata (Lamouroux) Papenfuss 1943a: 467, figs 1–15.
Lobophora nigrescens J. Agardh 1894a: 23, p1. 1 figs 7,8.
Thallus (Fig. 92A) medium to dark brown, drying dark brown to black, 4–10 (–14) cm long and as much across, decumbent (almost prostrate) to more or less erect, broadly flabellate, simple to irregularly lacerate or branched with clustered fronds, narrow and stupose below, attached by a matted, rhizoidal holdfast 0.2–1 cm across and 0.5–1.5 cm long; epilithic. Fronds complanate, flabellate, 1–4 cm across apically, 2–10 mm across below, faintly concentrically zoned with growth and hair lines. Growth- from an extensive marginal row of apical cells. Structure (5–) 7–9 (–11) cells and (120–)l 50–200 µm thick, cells in regular rows in transverse section but with the central layer of cells distinctly larger (Fig. 91G) and the cortical cells nearly all paired, with (3–) 4 (–6) cortical cells corresponding to each elongate medullary cell lengthwise (Fig. 91F) (the outer medullary cells often subdivided once lengthwise), (8–) 10–12(14) µm across in surface view and L/B 1–2 (–4); rhizoids moniliform with ovoid cells. Hair tufts (Fig. 91F) phaeophycean, on both sides of the thallus, scattered or more or less in concentric lines, hairs 15–2511m in diameter.
Reproduction: Sori of sporangia (Fig. 91F) scattered on both surfaces, irregularly ovate, (0.5–) 1–3 µm long and across, indusiate and without cellular paraphyses; sporangia clavate to pyriform, 100–150 (–180) µm long and 60–95 µm in diameter, without a stalk cell, forming eight (or occasionally four) spores. Oogonia in scattered sori, ovoid, without a stalk cell (Papenfuss 1943a, p. 465, figs 6,9,10). Antheridia unknown.
Type from the Antilles (Richard); in Herb. Lamouroux, CN.
Selected specimens: Pelsart I., Houtman Abrolhos, W. Aust., upper sublittoral (Womersley, 2.ix.1947; ADU, A5881). Nancy Cove, Rottnest I., W. Aust., 3 m deep (Walker, 16.v.1986; ADU, A57111). Cowaramup Bay, W. Aust., 2–3 m deep (Clarke & Engler, 1.ix.1979; ADU, A50654). Israelite Bay, W. Aust., drift (Wells, 10.xii.1974; ADU, A46095). Point Fowler, S. Aust., upper sublittoral pools (Womersley, 6.ii.1954; ADU, A19433). Port Stanvac, S. Aust., 4–5 m deep (Clarke, 17.v.1981; ADU, A54599). Aldinga, S. Aust., drift ( Womersley, 17.iv.1966; ADU, A30222). Middle R., Kangaroo I., S. Aust., drift ( Womersley, 8.i.1946; ADU, A3402). D'Estrees Bay, Kangaroo I., S. Aust., reef pools (Womersley, 24.viii.1950; ADU, A15347). Port Phillip Heads, Vic. ( Wilson, 12.i.I895; MEL, ADU, A8269). Flinders I., off Port Kembla, N.S.W., 6–8 m deep (Watson, 12.vii.1973; ADU, A43873).
Distribution: Widely distributed in tropical to temperate waters.
Extending from Western Australia around southern Australia to Aldinga, S. Aust., with one record from Port Phillip Heads, and from Port Kembla, N.S.W. northwards. Apparently absent from Tasmania. Generally found from low tide level (thallus then decumbent) to deep water (36 m) where the thallus is largely erect.
Taxonomic notes: Lobophora variegata is readily recognised by its form and the larger central layer of cells in the thallus, but varies from decumbent to erect depending on depth and habitat conditions.
AGARDH, J.G. (1894a). Analecta Algologica. Cont. I. Acta Univ. lund. 29, 1–144, Plates 1, 2.
ALLENDER, B.M. & KRAFT, G.T. (1983). The marine algae of Lord Howe Island (New South Wales): The Dictyotales and Cutleriales (Phaeophyta). Brunonia 6, 73–130.
PAPENFUSS, G.F. (1943a). Notes on algal nomenclature. II. Gymnosorus J. Agardh. Am. J. Bot. 30, 463–468.
WOMERSLEY, H.B.S. (1967). A critical survey of the marine algae of southern Australia. II. Phaeophyta. Aust. J. Bot. 15, 189–270.
The Marine Benthic Flora of Southern Australia Part II complete list of references.
Womersley, H.B.S. (14 December, 1987)
The Marine Benthic Flora of Southern Australia
©Board of the Botanic Gardens and State Herbarium, Government of South Australia
Illustrations in Womersley Part II, 1997: FIGS 91F,G, 92A.
Figure 91 enlarge
Fig. 91. A–C. Zonaria spiralis (ADU, A57082). A. Spiral branches with sporangial sori. B. Surface view of thallus with mostly paired cortical cells. C. Transverse section of thallus with sporangia and paraphyses. D,E. Zonaria turneriana (ADU, A57043). D. Surface view of thallus with paired cortical cells. E. Transverse section of thallus with sporangia and paraphyses. F,G. Lobophora variegata (ADU, A57111). F. Apical cell and segmentation of thallus, with phaeophycean hairs. G. Transverse section of thallus with sporangia.
Figure 92 enlarge
Fig. 92. A. Lobophora variegata (ADU, A57111). B. Scoresbyella profunda (ADU, A38067, holotype).
State Herbarium of South Australia