Electronic Flora of South Australia
Electronic Flora of South Australia
Census of SA Plants, Algae & Fungi
Identification tools

Electronic Flora of South Australia Species Fact Sheet

Lomathamnion epicodii Gordon 1972: 127, fig. 41.

Phylum Rhodophyta – Order Ceramiales – Family Ceramiaceae – Tribe Spermothamnieae

Selected citations: Silva et al. 1996: 417. Wollaston 1984: 296.

Thallus dark red-brown, tufted and spreading, 2–4 mm high, with prostrate filaments and erect, simple to sparingly branched, branches (Fig. 101A), 1–4 branches from each cell of prostrate filaments, tapering slightly above. Prostrate filaments attached by digitate haptera; epiphytic on Codium galeatum. Structure. Prostrate filaments 30–45 µm in diameter, cells L/D 1–4; erect filaments with median cells 30–40 µm in diameter, cells L/D 2–6, terminal cells often hair like. Cells multinucleate; rhodoplasts discoid.

Reproduction: Gametophytes dioecious. Female axes (3–) 4 (–12) cells long, borne laterally on lower cells of erect filaments or occasionally on the prostrate axes, with the last 3 cells short and the subhypogenous cell 2–3 times as long. Subapical cell bearing 2 periaxial cells, one sterile and one (the supporting cell) with a sterile apical cell and a lateral carpogonial branch (Fig. 101B). Post-fertilization the supporting cell cuts off an auxiliary cell which produces 2–4 gonimoblast cells each dividing to form 3–4 cells which either directly or on subdivision become ovoid carposporangia (Fig. 101C) 25–50 µm in diameter. Very little fusion occurs between cells of the procarp or gonimoblast, and a fusion cell is not produced. The apical cell, sterile periaxial cell, and sterile cell on the supporting cell all normally remain undivided. Spermatangial heads (Fig. 10ID, E) ovoid, 40–55 µm in diameter, borne on unicellular pedicels laterally on lower cells of erect filaments or directly on prostrate filaments.

Tetrasporangia (Fig. 101A) terminal on unicellular pedicels produced laterally on erect filaments, single or in opposite pairs, 40–50 µm in diameter, tetrahedrally divided but often almost cruciately arranged.

Type from Seal Bay, Kangaroo I., S. Aust., epiphytic on Codium galeatum (Gordon, 31.x.1966); holotype and isotypes in AD, A30961.

Selected specimens: (all on Codium galeatum): 7 mile Beach, N of Dongara, W. Aust., drift (Womersley, 17.ix.1979; AD, A51375). Hopetoun, W. Aust., drift (Gordon, 20.xi.1968; AD, A33182). Head of Great Australian Bight, S. Aust., drift (Gordon, 3.xi.1968; AD, A33186 - "Marine Algae of southern Australia" No. 108c). Wedge I., S. Aust., 8–10 m deep (Baldock, 29.xii.1963; AD, A27251). Port Elliot, S. Aust., drift (WoeIkerling, 8.v.1968; AD, A31392). Seal Bay, Kangaroo I., S. Aust., drift (Womersley, 21.i.1965; AD, A28897) and (Woelkerling, 20.xi.1967; AD, A32053 - "Marine Algae of southern Australia" No. 108a) and (Wollaston, 22.xi.1968; AD, A32175 - "Marine Algae of southern Australia" No. 108b). Stanley Beach, S coast Kangaroo I., S. Aust., drift (Womersley, 6.ii.1957; AD, A20909). Port MacDonnell, S. Aust., drift (Womersley, 19.viii.1953; AD, Al 8993). Point Roadknight, Vic., drift (Womersley, 6.vi.1953; AD, Al 8797). Point Lonsdale, Vic., drift (Womersley, 21.xi.1990; AD, A60800). Cat Bay, Phillip I., Vic., drift (Womersley, 10.iv.1959; AD, A32151).

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

Distribution: Dongara, W. Aust., to Phillip I., Victoria.


GORDON, E.M. (1972). Comparative morphology and taxonomy of the Wrangelieae, Sphondylothamnieae and Spermothamnieae (Ceramiaceae, Rhodophyta). Aust. J. Bot. suppl. 4, 1–180.

SILVA, P.C., BASSON, P.W. & MOE, R.L. (1996). Catalogue of the Benthic Marine Algae of the Indian Ocean. (University of California Press: Berkeley, Los Angeles & London.)

WOLLASTON, E.M. (1984). Species of Ceramiaceae (Rhodophyta) recorded from the International Indian Ocean Expedition, 1962. Phycologia 23, 281–299.

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

Author: H.B.S. Womersley

Publication: Womersley, H.B.S. (24 December, 1998)
The Marine Benthic Flora of Southern Australia
Rhodophyta. Part IIIC. Ceramiales – Ceramiaceae, Dasyaceae
©State Herbarium of South Australia, Government of South Australia

Illustration in Womersley Part IIIA, 1998: FIG. 101.

Figure 101 image

Figure 101   enlarge

Fig. 101. Lomathamnion epicodii (A, B, AD, A20909; C, AD, A28897; D, E, AD, A30961). A. Prostrate and erect axes with tetrasporangia. B. Mature procarp system. C. Young carposporophyte. D. Prostrate and erect axes, with spermatangial heads. E. Longitudinal section of a spermatangial head. (All as in Gordon 1972, courtesy of Aust. J. Bot.)

Disclaimer Copyright Disclaimer Copyright Email Contact:
State Herbarium of South Australia
Government of South Australia Government of South Australia Government of South Australia Department for Environment and Water