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Electronic Flora of South Australia Species Fact Sheet

Lophothalia hormoclados (J. Agardh) J. Agardh 1890: 59.

Phylum Rhodophyta – Family Rhodomelaceae – Tribe Lophothalieae

Selected citations: De Toni 1903: 1019. Falkenberg 1901: 537. Kylin 1956: fig, 405A. Lucas 1909: 43; 1929a: 22. Lucas & Perrin 1947: 286. May 1965: 378. Schmitz 1893: 219. Shepherd 1983: 83. Wilson 1892: 166.


Dasya hormoclados J. Agardh 1841: 32; 1863: 1188. Harvey 1849a: 65, pl. 26; 1863, synop.: xxiv. Sonder 1880: 36.

Eupogonium (?) hormoclados (J. Agardh) Kützing 1849: 799.

Thallus (Fig. 121A) medium to dark red-brown, fading to grey-red, 20–50 cm high, much branched with denuded, cartilaginous, branched axes 1–3 (–4) mm in diameter bearing apically and laterally (proliferous on older axes) dense, soft, tufts 2–5 cm long of slender, terete, laterals, irregularly radially branched for 3–5 orders, basally 200–500 µm in diameter and tapering to 100–200 µm in diameter below apices; cortication (Fig. 121C) commencing close to apices but slight above, becoming thick on axes. Laterals clothed with simple, relatively robust rhodoplastic trichoblasts (Fig. 121B) arising singly from each segment, adventitious filaments absent or rare. Axes and laterals usually infested with a hydroid (Halecium sp.) (Fig. 121B). Holdfast discoid, becoming fibrous and 1–3 cm across; epilithic or on jetty piles. Structure monopodial with 6 or 7 pericentral cells which become separated by smaller cells and inconspicuous in transverse section of older branches. Trichoblasts tapering gradually throughout or more so apically, 50–130 µm in diameter below with basal cells L/D 1–1.5, increasing to L/D 3–4 (–8) in mid and upper cells, then tapering to subterminal cells 15–20 µm in diameter, terminal cells pointed. Cells multinucleate; rhodoplasts discoid, becoming chained.

Reproduction: Gametophytes dioecious. Procarps developing on a lower cell of trichoblasts, this and lower cells becoming polysiphonous. Carposporophytes with a basal fusion cell and branched gonimoblast filaments with clavate terminal carposporangia 30–45 µm in diameter, replaced from below. Cystocarps (Fig. 121D) globular, 700–1000 µm in diameter, with a short stalk and no (or slight) neck; pericarp ostiolate, 2 cells thick. Spermatangial organs (Fig. 121E) densely aggregated, covering lower cells of trichoblasts with 1–3 basal sterile cells and a terminal sterile filament; fertile parts 200–400 long and 40–90 µm in diameter.

Tetrasporangia (Fig. 121F) occur in lesser ultimate branch systems 1–2 mm long and 90–180 µm in diameter, bearing a trichoblast from each segment; tetrasporangia in decussate pairs, 60–120 µm in diameter, with 3 cover cells.

Type from "Nov. Holl" (Herb. Binder); holotype in Herb. Agardh, LD, 42012. Probable isotype in Herb. Sonder, MEL, 1005957 (ex Herb. Binder).

Selected specimens: Fowlers Bay, S. Aust., 15 m deep (Edyvane, 19.vi.1994; AD, A64433). Ward I., S. Aust., 18–23 m deep (Shepherd, 3.iii.1980; AD, A50908). Schnapper Point, Port Lincoln, S. Aust., 6–8 m deep (Baldock, 1.i.1964; AD, A27094). N Spencer Gulf, S. Aust., 11 m deep (Shepherd, 4.ix.1973; AD, A44108). Tiparra reef, S. Aust., 7 m deep (Shepherd, 12.i.1978; AD, A49397). Investigator Strait, S. Aust., 33 m deep (Watson, 24.i.1971; AD, A41077). Outside Tapley Shoal, Edithburg, S. Aust., 15 m deep (Shepherd, 2.ii.1969; AD, A33495). Off Outer Harbor, S. Aust., 16 m deep (Loan, 9.viii.1963; AD, A26651). Off Grange, S. Aust., on tyre reef, 20 m deep (Branden, 5.x.1985: AD, A56804-"Marine Algae of southern Australia" No. 421). Aldinga, S. Aust., drift (Womersley, 7.ix.1986; AD, A57138). Granite I., Encounter Bay, S. Aust., eastern side of causeway, 7–10 m deep (Edyvane, 8.viii.1982; AD, A53199). Pennington Bay, Kangaroo I., S. Aust., drift (Womersley, 22.viii.1954; AD, A19762). Gypsum Wharf, Ballast Head, Kangaroo I., S. Aust., on jetty piles, 0–5 m deep (Kraft, t, 16.vii.1972; AD, A42454). Penneshaw, Kangaroo I., S. Aust., 7 m deep on jetty (Lavers, 14.ix.1996; AD, A66784). Robe, S. Aust., on jetty piles, 3 m deep (Collings & Hotchkiss, 26.ix.1992; AD, A62826). Nelson, Vic., drift (Womersley, 29.xii.1981; AD, A52864). Off Redcliffe, Phillip I., Vic., 5 m deep (AIMS-NCI Q66C-3382-R; 12.ii.1990; AD, A60364). Walkerville, Vic., drift (Sinkora A2290, 6.iii.1976; AD, A48445). Bemm reef, E Vic., 15–17 m deep (Kraft & Foard, 8.ii.2001; MELU, K11096). Low Head, Tas. (Perrin, 25.x.1937; AD, A9031). Charlotte Cove, SE Tas, 9 m deep (Edgar, 6.x.1999; AD, A68349).

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

Distribution: Fowlers Bay, S. Aust., to Bemm reef, Vic., and around Tasmania.


AGARDH, J.G. (1841). In historiam algarum symbolae. Linnaea 15, 1–50, 443–457.

AGARDH, J.G. (1863). Species Genera et Ordines Algarum. Vol. 2, Part 3, pp. 787–1291. (Gleerup: Lund.)

AGARDH, J.G. (1890). Till algernes systematik. Acta Univ. lund. 26(3), 1–125, Plates 1–3.

DE TONI, G.B. (1903). Sylloge Algarum omnium hucusque Cognitarum. Vol. 4. Florideae. Sect. 3. pp. 775–1521 + 1523–1525. (Padua.)

FALKENBERG, P. (1901). Die Rhodomelaceen des Golfes von Neapel und der angrenzenden Meeres-abschnitte. Fauna und Flora des Golfes von Neapel. Monogr. 26. (Friedländer: Berlin.)

HARVEY, W.H. (1849a). Nereis Australis, pp. 65–124, Plates 26–50. (Reeve: London.)

HARVEY, W.H. (1863). Phycologia Australica. Vol. 5, Plates 241–300, synop., pp. i-lxxiii. (Reeve: London.)

KÜTZING, F.T. (1849). Species Algarum. (Leipzig.)

KYLIN, H. (1956). Die Gattungen der Rhodophyceen. (Gleerups: Lund.)

LUCAS, A.H.S. & PERRIN, F. (1947). The Seaweeds of South Australia. Part 2. The Red Seaweeds. (Govt Printer: Adelaide.)

LUCAS, A.H.S. (1909). Revised list of the Fucoideae and Florideae of Australia. Proc. Linn. Soc. N.S.W. 34, 9–60.

LUCAS, A.H.S. (1929a). The marine algae of Tasmania. Pap. Proc. R. Soc. Tasm. 1928, 6–27.

MAY, V. (1965). A census and key to the species of Rhodophyceae (red algae) recorded from Australia. Contr. N.S. W. Natl Herb. 3, 349–429.

SCHMITZ, F. (1893). Die gattung Lophothalia, J. Ag. Ber. Deutsch. Bot. Ges. 11, 212–232.

SHEPHERD, S.A. (1983). Benthic communities of upper Spencer Gulf, South Australia. Trans. R. Soc. S. Aust. 107, 69–85.

SONDER, O.W. (1880). In Mueller, F., Fragmenta Phytographiae Australiae. Supplementum ad volumen undecinum: Algae Australianae hactenus cognitae, pp. 1–42, 105–107. (Melbourne.)

WILSON, J.B. (1892). Catalogue of algae collected at or near Port Phillip Heads and Western Port. Proc. R. Soc. Viet. 4, 157–190.

The Marine Benthic Flora of Southern Australia Part IIID complete list of references.

Author: H.B.S. Womersley & M.J. Parsons

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.

Illustration in Womersley Part IIIA, 2003: FIG. 121.

Figure 121 image

Figure 121   enlarge

Fig. 121. Lophothalia hormoclados (A, C, AD, A62826; B, F, AD, A26651; D, E, AD, A56804). A. Habit. B. Branches with tetrasporangia and dark line of the endophytic hydroid. C. Transverse section of axis. D. Cystocarps. E. Spermatangial organs. F. Branch bearing trichoblasts and with decussate tetrasporangia.

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