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Electronic Flora of South Australia Species Fact Sheet
Phylum Rhodophyta – Family Rhodomelaceae – Tribe Polyzonieae
Selected citations: Adams 1994: 314, pl. 107 top left. Scagel 1962: 1025, figs 18, 19, 41–44.
Synonyms
Polyzonia harveyana Decaisne ex Harvey 1849a: 72. Raoul 1846: 32, nomen nudum.
Polyzonia incisa var. harveyana (Decaisne ex Harvey)J. Agardh 1863: 1166.
Euzoniella harveyana (Decaisne ex Harvey)Falkenberg 1901: 366, fig. 7. De Toni 1903: 1030. Guiler 1952: 106. Lucas 1909: 44. May 1949: 297; 1965: 379. Scagel 1953: 82.
Thallus (Fig. 141A) dark red-brown, largely prostrate or basally attached and free above, 0.5–2 cm long (to 6 cm in New Zealand), indeterminate axes occasionally branched, bearing distichously alternate determinate laterals 0.5–1.5 mm long from each second segment; determinate laterals (Fig. 141B, C) pectinate to digitate, more or less complanately branched with the lower 1–2 (–3) branches similarly branched. Lateral indeterminate axes arise endogenously from the segment above a determinate lateral and separated by (2–) 3 determinate laterals. Attachment by rhizoids (Fig. 141B); epiphytic, or epilithic? Structure. Apices relatively straight, apical cells dome-shaped, 15–20 µm in diameter. Indeterminate axes with 6 pericentral cells, 70–240 µm in diameter, segments L/D 0.6–1.2. Determinate laterals in lower segments with 3 pericentral cells, segments (60–) 80–120 µm in diameter and L/D 0.5–1, tapering above to 3 cells broad, polysiphonous to the 1 (–3) terminal cells, mucronate. Trichoblasts absent. Rhizoids in pairs from adjacent pericentral cells, not cut off, with a common sheath and digitate haptera. Cells uni- to multinucleate; rhodoplasts discoid.
Reproduction: Procarps on a lower segment of the basal branch of a determinate lateral. Carposporophytes with a small basal fusion cell and short gonimoblast with clavate terminal carposporangia, 50–90 µm in diameter. Cystocarps (Fig. 141D) ovoid to slightly urceolate, 500–750 µm in diameter, sessile on determinate laterals; pericarp 2 cells thick, ecorticate, outer cells angular, L/D 1–2. Spermatangia unknown.
Tetrasporangial branches (Fig. 141E) arising from the axial segment above a determinate lateral, 0.9–2 mm long and 100–180 µm in diameter, simple or with lower branches, bearing branched spinous determinate laterals from each second segment, more or less distichously. Tetrasporangia in long rows of 8–25, occupying most of the segment width, 70–130 µm in diameter, with 3 (divided) cover cells.
Type from New Zealand, on Pterocladia lucida (Raoul); lectotype in Herb. Harvey, TCD? Adams (1994, p. 314) suggests the type probably came from Akaroa.
Selected specimens: Cape Woolamai, Vic., on Hildenbrandia, 13 m deep (Riddle, 17.ii.1990; AD, A60084). Stapleton Point, Prosser Bay, Tas., on Sonderophycus, 6–8 m deep (Shepherd, 10.ii.1970; AD, A35752). Port Arthur, Tas., on Hildenbrandia expansa, 10 m deep (McKenna, 1.iii.1990; AD, A60433). Safety Cove, Port Arthur, Tas., on non-geniculate coralline, 7 m deep (Brown & Kenchington, 16.x.1986; AD, A57727). Fluted Cape, Bruny I., Tas., on non-geniculate coralline, 23 m deep (Shepherd, 12.ii.1972; AD, A41927).
Distribution: In southern Australia, from Cape Woolamai, Vic., and SE Tasmania. New Zealand.
Taxonomic notes: This New Zealand species occurs also in SE Australia, mainly on cartilaginous algae or corallines. It is clearly distinguished from the other species of Dasyclonium by the branched lower branches on the determinate laterals, and also the long series of tetrasporangia.
Polyzonia harveyana was first mentioned (as a nomen nudum) in Raoul 1846-"Choix de Plantes de la Nouvelle-Zelande", a publication which Harvey (1849, p. 72) referred to as "Pl. Nov. Zeal." (M.J. Parsons, pers. comm.).
References:
ADAMS, N.M. (1994). Seaweeds of New Zealand. (Cant. Univ. Press: Christchurch.)
AGARDH, J.G. (1863). Species Genera et Ordines Algarum. Vol. 2, Part 3, pp. 787–1291. (Gleerup: Lund.)
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.)
GUILER, E.R. (1952). The marine algae of Tasmania. Checklist with localities. Pap. Proc. R. Soc. Tasmania 86, 71–106.
HARVEY, W.H. (1849a). Nereis Australis, pp. 65–124, Plates 26–50. (Reeve: London.)
KYLIN, H. (1956). Die Gattungen der Rhodophyceen. (Gleerups: Lund.)
LUCAS, A.H.S. (1909). Revised list of the Fucoideae and Florideae of Australia. Proc. Linn. Soc. N.S.W. 34, 9–60.
MAY, V. (1949). Studies on Australian marine algae. IV. Further geographical records. Proc. Linn. Soc. N.S.W. 73, 293–297.
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.
RAOUL, M.E. (1846). “Choix de Plantes de la Nouvelle-Zélande.” (Fortin, Masson: Paris.)
SCAGEL, R.F. (1953). A morphological study of some dorsiventral Rhodomelaceae. Univ. Calif. Pubis Bot. 27, 1–108.
SCAGEL, R.F. (1962). The genus Dasyclonium J. Agardh. Canadian J. Bot. 40, 1017–1040, Plates i-iv.
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. 141.
Figure 141 enlarge
Fig. 141. Dasyclonium harveyanum (A, AD, A57727; B, AD, A60433; C–E, AD, A41927). A. Habit. B. Indeterminate branch with rhizoids and determinate laterals with branched basal branches. C. As in B. D. Cystocarps. E. Tetrasporangia within an indeterminate branch bearing determinate branches.
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