Electronic Flora of South Australia Species Fact Sheet

Lophosiphonia obscura (C. Agardh) Falkenberg in Schmitz & Falkenberg 1897: 460.

Phylum Rhodophyta – Family Rhodomelaceae – Tribe Polyzonieae

Selected citations: Silva et al. 1996: 525. Wynne 1998: 44.

Synonyms

Hutchinsia obscura C. Agardh 1828: 108.

Polysiphonia subadunca Kützing 1843: 418; 1849: 805; 1863: 11, pl. 32a-c. J. Agardh 1863: 1064.

Lophosiphonia subadunca (Kützing) Falkenberg 1901: 496, pl. 9 figs 21–24. Beanland & Woelkerling 1982: 98. Børgesen 1939: 132. Cribb 1956b: 139. De Toni 1903: 1067. Silva in Silva et al. 1996: 921.

Thallus (Fig. 147A) of prostrate filaments with upwardly curved apices, bearing dorsally terete erect branches 1–2 cm high, simple or with few branches, with few apical trichoblasts. Attachment by rhizoids; epiphytic on mangrove pneumatophores. Structure. Apical cells dome-shaped, 20–25 µm in diameter, axial cells cutting off 6 pericentral cells (Fig. 147C), ecorticate. Prostrate and erect filaments 80–100 µm in diameter, segments L/D 0.6–1. Erect branches arise endogenously. Rhizoids (Fig. 147B) not cut off from the parent cell, 35–45 µm in diameter, with divided (probably multicellular) haptera. Cells with discoid rhodoplasts.

Reproduction: Not observed in Australian collections and apparently rare elsewhere. Female plants little known (Falkenberg 1901, p. 498). Spermatangial organs borne on trichoblasts, lanceoid (Falkenberg 1901, pl. 9 figs 23, 24).

Tetrasporangia borne in upper segments of erect branches, spirally arranged, one per segment, 50–80 µm in diameter (Børgesen 1939, p. 132).

Type from Cadiz, Spain; in Herb. Agardh, LD.

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

Distribution: Wallaroo, S. Australia.

Mediterranean and Atlantic Europe, NW Indian Ocean. W subtropical Atlantic. Queensland.

Taxonomic notes: Southern Australian specimen: 5 km S of Wallaroo, S. Aust., on Avicennia marina pneumatophores (Beanland, 15.vi.1981; LTD, 12376 and AD, A69062).

Use of the name L. obscura follows Silva in Silva et al. (1996, p. 921). Cribb (1956b, p. 140) considered that Kützing (1863, pl. 32C) showed a rhizoid cut off from the pericentral cell; this figure, however, is at best vague on this feature.

The above collection is the only record of the species from southern Australia.

References:

AGARDH, C.A. (1828). Species Algarum. Vol. 2. (Mauritius: Greifswald.)

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

BØRGESEN, F. (1939). Marine algae from the Iranian Gulf, especially from the innermost part near Bushire and the Island Kharg. Danish Scientific lnvestiagions in Iran, Part 1, 47–141.

BEANLAND, W.R. & WOELKERLING, W.J. (1982). Studies on Australian mangrove algae: IT. Composition and geographical distribution of communities in Spencer Gulf, South Australia. Proc. R. Soc. Vict. 94, 89–106.

CRIBB, A.B. (1956b). Records of marine algae from south-eastern Queensland II. Polysiphonia and Lophosiphonia. Univ. Qld Pap. Dept Bot. 3(16), 131–147.

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.)

KÜTZING, F.T. (1843). Phycologia generalis. (Leipzig.)

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

KÜTZING, F.T. (1863). Tabulae Phycologicae. Vol. 13. (Nordhausen.)

SCHMITZ, F. & FALKENBERG, P. (1897). Rhodomelaceae. In Engler, A. & Prantl, K., Die natürlichen Pflanzenfamilien. T.1. Abt. 2, pp. 421–480. (Englemann: Leipzig.)

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

WYNNE, M.J. (1998). A checklist of benthic marine algae of the tropical and subtropical western Atlantic: first revision. Nova Hedwigia Beih. 116, 1–155.

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

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. 147 A–C.

Figure 147   enlarge

Fig. 147. A–C. Lophosiphonia obscura (AD, A69062). A. Indeterminate (horizontal) branch with 2 juvenile indeterminate branches, all bearing determinate laterals. B. Indeterminate branch with a rhizoid. C. Transverse section of branch with 6 pericentral cells. D–G. Ophidocladus simpliciusculus (D, AD, A48870; E, AD, A32907; F, G, AD, A42969). D. Habit. E. Apices of erect branches with trichoblasts and tetrasporangia. F. Apex of indeterminate prostrate axis with erect branches and rhizoids. G. Erect branches with opposite tetrasporangia.

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