Electronic Flora of South Australia Species Fact Sheet

Lobospira bicuspidata Areschoug 1854: 364.

Phylum Phaeophyta – Order Dictyotales – Family Dictyotaceae – Tribe Zonarieae

Selected citations: Edelstein & Womersley 1975: 149, figs 1–5. Harvey 1858: p1.34. Womersley 1967: 215.

Thallus (Fig. 73A) medium to dark brown, 5–25 cm long, with numerous, much branched, spirally twisted axes from an entangled base. Axes compressed, becoming subterete below, 0.5–1.5 mm in diameter, with irregularly radial laterals, bearing pointed or bicuspid, compressed, determinate ramuli (0.5–) 1–2 (–3) mm long and (0.5–) 1–1.5 (–3) mm broad, 3–5 cells thick (Fig. 72L), on a phyllotaxis of 1/3, denuded below. Attachment of thallus by long branches with lateral, recurved, tendrils, emitted from lower axes; usually epiphytic. Growth (Fig. 72K) by short rows of cells at the apices of the axes or laterals. Cortical cells of ramuli 20–40 µm across, L/B 1–2. Phaeophycean hair tufts in centre of branchlets, often remaining undeveloped.

Reproduction: Tetrasporangia (Figs 72L, 73B) scattered on ramuli and branches, 80–100(120) µm in diameter, transformed from surface cells and sunken (slightly protruding when dried), dividing into four shortly before their loss. Sexual reproduction unknown.

Type from Port Adelaide, S. Aust.; in Herb. Areschoug, S (not located).

Selected specimens: Nickol Bay, W. Aust., 1880/1881 (MEL 17087–17089, 17092). Port Denison, W. Aust., reef pools (Gordon, 8.xi.1968; ADU, A33218). Natural Jetty, Rottnest I., W. Aust. (Smith 29, 25.xi.1945; ADU, A2097). Aldinga, S. Aust. (Edelstein & Kraft, 27.v.1972; ADU, A42264). Stanley Beach, Kangaroo I., S. Aust. (Edelstein & Kraft 126, 25.iv.1972; NRCC, 10623). Carpenter Rocks, S. Aust., in shaded pools (Womersley, 5.ii.1970; ADU, A35179-"Marine Algae of southern Australia" No.38). Double Corner Beach, Portland, Vic., drift (Beauglehole, 14.vii.1951; ADU, A21768). Walkerville, Vic., drift (Sinkora A1590, 23.ii9.iii.1972; ADU, A43104). East Cove, Deal I., Bass Str. (Shepherd & Lewis, 5.v.1974; ADU, A45245). Eden, N.S.W. (Lucas, Jan. 1910; NSW).

Distribution map based
on current data relating to
specimens held in the
State Herbarium of SA

Distribution: From Nickol Bay, W. Aust., around southern Australia to Eden, N.S.W.

Taxonomic notes: Lobospira is a distinctive member of the Zonarieae, but apparently not common around Tasmania. It is often common just below low tide level and extending to 13 m deep.

References:

ARESCHOUG, J.E. (1854). Phyceae novae et minus cognitae in maribus extraeuropaeis collectae. Ada Reg. Soc. Sci. Upsala, Ser. III, 1, 329–372.

EDELSTEIN, T. & WOMERSLEY, H.B.S. (1975). The thallus and spore development of Lobospira bicuspidata Areschoug (Dictyotales: Phaeophyta). Trans. R. Soc. S. Aust. 99, 149–156.

HARVEY, W.H. (1858). Phycologia Australica. Vol. I, Plates 1–60. (Reeve: London.)

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.

Author: H.B.S. Womersley

Publication: Womersley, H.B.S. (14 December, 1987)
The Marine Benthic Flora of Southern Australia
Part II
©Board of the Botanic Gardens and State Herbarium, Government of South Australia

Illustrations in Womersley Part II, 1997: FIGS 72K,L, 73A,B.

Figure 72   enlarge

Fig. 72. A–E. Pachydictyon polycladum (ADU, A16099). A. Lateral branch system with tetrasporangia and hair tufts below branchings. B. Transverse section of branch with an undivided sporangium. C. Transverse section of older axis with multilayered cortex. D. Upper branches of plant with oogonia. E. Transverse section of branch with oogonial sorus. F–J. Pachydictyon paniculatum (F,G, ADU, A29663; H,J, ADU, A43709; I, ADU, A32634). F. Lateral branch system with tetrasporangia and hair tufts. G. Transverse section of branch with tetrasporangia. H. Transverse section of older axis with multilayered cortex. I. Upper branches of plant with antheridial sori. J. Transverse section of branch With antheridial sorus. K,L. Lobospira bicuspidata (ADU, A42264). K. Apex of axis with apical (a.m.) and lateral (1.m.) meristems and two laterals, the right-hand one becoming bicuspid. L. Transverse section of a lateral with undivided sporangia.

Figure 73   enlarge

Fig. 73. A. Lobospira bicuspidata (NRCC, 10623). B. Thal lus with tetrasporangia and released spores at lower left (ADU, A42264). C. Padina gymnospora (ADU, A50606). D. Padina fraseri (ADU, A56877).

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