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Electronic Flora of South Australia Species Fact Sheet
Phylum Rhodophyta – Family Rhodomelaceae – Tribe Polysiphonieae
Selected citations: J. Agardh 1863: 968. De Toni 1903: 877; 1924: 394. Guiler 1952: 103. Hooker & Harvey 1847: 399. Huisman & Walker 1990: 440. Kützing 1849: 823; 1863: 27, pl. 88a-c. Lucas 1909: 41; 1929a: 21; 1929b: 51. Lucas & Perrin 1947: 267. Mazza 1909: No. 284. Meñez 1964: 213, fig. 3? Reinbold 1897: 57. Silva et al. 1996: 543. Sonder 1853: 701; 1855: 524; 1880: 34. Tisdall 1898: 514. Wilson 1892: 167. Womersley 1956: 82, 83; 1979: 476, fig. 4D–G.
Synonym
Polysiphonia flavescens Zanardini 1874: 490. De Toni 1903: 955; 1924: 402. Guiler 1952: 103. Lucas 1909: 41; 1929a: 21. Lucas & Perrin 1947: 270.
Thallus (Fig. 80D) red-brown, usually 4–20 cm high, with a single, erect, basal axis (occasionally a slight prostrate part) and profusely branched above (often denuded below in older plants) subdichotomously to laterally to form dense, fastigiate to spreading, soft tufts. Holdfast discoid, small; commonly epiphytic on Posidonia, Heterozostera, Halophila or larger algae. Structure. Basal axis 300–700 µm in diameter with segments L/D 0.3–1, attached by unicellular rhizoids cut off from the lower pericentral cells; branches above the basal axis 250–500 µm in diameter with segments L/D 1–4 (–8), decreasing in lesser branches to 100–150 µm in diameter with segments L/D 0.7–3 and to 30–50 µm in diameter with segments L/D about 1 close to the apices; apices straight, apical cell and trichoblasts prominent; lateral branches arising close to apices from the basal cell of trichoblasts, with the trichoblast usually remaining lateral to the new branch rather than outside it; cicatrigenous branches often present below. Pericentral cells 4, elongate throughout the thallus except within a few segments of apices; ecorticate except for slight cortication in older parts near the base of the erect axis by filaments of relatively short cells originating from the corners of the pericentral cells and lying lengthwise over the junction; trichoblasts (or scar cells) formed on every segment, with a divergence of 1/4, relatively slender, basal cells 8–12 µm in diameter. Rhodoplasts discoid to angular; scattered or commonly in irregular chains.
Reproduction: Gametophytes dioecious. Carposporophytes with a slight basal fusion cell and short, branched, gonimoblast with shortly clavate terminal carposporangia 25–50 µm in diameter. Cystocarps (Fig. 80E) short-stalked, globular to ovoid, not or slightly urceolate, 250–400 µm in diameter; pericarp ostiolate, 2 cells thick, outer cells isodiametric, angular. Spermatangial branches (Fig. 80F) developing as one branch of a trichoblast, elongate-ovoid to cylindrical, (80–) 120–200 µm long and 35–50 µm in diameter, without a sterile apical cell, or with an inconspicuous one.
Tetrasporangia (Fig. 80G) forming gently spiral series in upper branches (often extending below one to several laterals), slightly to prominently swelling and distorting the branch, subspherical to ovoid, 50–70 µm in diameter.
Type from Tasmania, on larger algae (Gunn); lectotype in BM.
Selected specimens: Salmon Bay, Rottnest I., W. Aust., on Sargassum, drift (Parsons, 12.xi.1968; AD, A33387). Muston, American R. inlet, Kangaroo I., S. Aust., 2–3 m deep (Womersley, 21.xi.1968; AD, A32929) and 4–5 m deep (Shepherd, 29.xii.1977; AD, A48954). Taroona, Tas., 1–3 m deep (Shepherd, 19.iii.1975; AD, A46226).
Distribution: Rottnest I., W. Aust., around southern Australia and Tasmania to Port Phillip, Victoria.
Indian Ocean (see Silva et al. 1996: 543); Pacific Ocean? (Abbott & Hollenberg 1976: 688).
Taxonomic notes: The type material of P. mollis in BM consists of a sheet with two specimens, both 'Gunn 1316'. The lower is selected as lectotype; the upper isolectotype is attached to a Eucalyptus leaf. Another specimen from V.D.L. is labelled 'Polysip. mollis var'. Two features that are not convincingly shown in the type are the single erect base and the origin of the lateral branches. However, Harvey in his original description referred to 'Root scutate. Fronds erect, solitary, or approximating' and in the recent material examined the erect basal axis attached by a cluster of rhizoids is a general feature. The origin of branches from trichoblasts is a difficult feature to discern in herbarium specimens, but a careful examination of the type shows that almost certainly branches do originate from the basal cell of trichoblasts, as they clearly do in fresh collections which in other features agree well with the type.
P. mollis is characterised by the erect base and branches which taper from 300 µm or more near the base to 30–50 µm in diameter close to the apices, the branching associated with the trichoblasts, and the soft, readily disintegrating nature of the thallus. It is a common epiphyte in relatively calm situations or where a current flows.
P. mollis has been recorded (often doubtfully) from many parts of the tropical Indian and Pacific Oceans, e.g. from Japan by Yendo (1916b, p. 261), now placed under P. japonica Harvey by Yoshida (1998, p. 1067); from Sri Lanka by Durairatnam (1961, p. 70) on the basis of a sterile specimen ; from Mauritius by Børgesen (1945, p. 30) but see Silva et al. (1996, p. 543); from Bangladesh by Islam (1976, p. 64); from the central Pacific and from Mexico by Hollenberg (1961, p. 359, pl. 4 fig. 2; 1968a, p. 69, fig. 43) but referred by Abbott (1999, p. 432) to P. tongatensis Harvey ex Kützing; and from Queensland by Askenasy (1894, p. 13, pl. 3 fig. 13, pl. 4 figs 20–22) and by Cribb (1956b, p. 131, pl. 4 figs 1–4, p1.5). However, it appears unlikely that P. mollis occurs outside southern Australia.
An isotype of P. flavescens Zanardini from Georgetown, Tas. (Goodwin), in Herb. Zanardini, Venice, is identical with P. mollis and comes from the same type locality.
References:
ABBOTT, I.A. & HOLLENBERG, G.J. (1976). Marine Algae of California. (Stanford Univ. Press: Stanford.)
ABBOTT, I.A. (1999). Marine Red Algae of the Hawaiian Islands. (Bishop Museum Press: Honolulu, Hawai'i.)
AGARDH, J.G. (1863). Species Genera et Ordines Algarum. Vol. 2, Part 3, pp. 787–1291. (Gleerup: Lund.)
ASKENASY, E. (1894). Über einige australische Meeresalgen. Flora 78, 1–18, Plates 1–4.
BØRGESEN, F. (1945). Some marine algae from Mauritius III. Rhodophyceae. Part 4 Ceramiales. K. Dan. Vidensk. Selsk. Biol. Meddr. 19(10), 1–68.
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.)
DE TONI, G.B. (1924). Sylloge Algarum omnium hucusque Cognitarum. Vol. 6. Florideae. (Padua.)
DURAIRATNAM, M. (1961). Contribution to the study of the marine algae of Ceylon. Fisheries Research Station, Ceylon, Bull. 10, 1–181.
GUILER, E.R. (1952). The marine algae of Tasmania. Checklist with localities. Pap. Proc. R. Soc. Tasmania 86, 71–106.
HARVEY, W.H. (1847). Nereis Australis, pp. 1–69, Plates 1–25. (Reeve: London.)
HARVEY, W.H. (1855a). Some account of the marine botany of the colony of Western Australia. Trans. R. Jr. Acad. 22, 525–566.
HARVEY, W.H. (1859b). Algae. In Hooker, J.D., The Botany of the Antarctic Voyage. III. Flora Tasmaniae. Vol. II, pp. 282–343, Plates 185–196. (Reeve: London.)
HARVEY, W.H. (1863). Phycologia Australica. Vol. 5, Plates 241–300, synop., pp. i-lxxiii. (Reeve: London.)
HOLLENBERG, G.J. (1961). Marine red algae of Pacific Mexico. Part 5. The genus Polysiphonia. Pacif. Nat. 2(6), 345–375.
HOLLENBERG, G.J. (1968a). An account of the species of Polysiphonia of the central and western Tropical Pacific Ocean. 1. Oligosiphonia. Pacif. Sci. 22, 56–98.
HOOKER, J.D. & HARVEY, W.H. (1847). Algae Tasmanicae. Lond. J. Bot. 6, 397–417.
HUISMAN, J.M. & WALKER, D.I. (1990). A catalogue of the marine plants of Rottnest Island, Western Australia, with notes on their distribution and biogeography. Kingia 1, 349–459.
ISLAM, A.K.M.N. (1976). Contribution to the study of the marine algae of Bangladesh. Bibl. Phycol. Vol. 19.
KÜTZING, F.T. (1849). Species Algarum. (Leipzig.)
KÜTZING, F.T. (1863). Tabulae Phycologicae. Vol. 13. (Nordhausen.)
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.
LUCAS, A.H.S. (1929b). A census of the marine algae of South Australia. Trans. R. Soc. S. Aust. 53, 45–53.
MAZZA, A. (1909). Saggio di Algologia Oceanica. Nuova Notarisia 20, Nos. 275–308.
MEÑEZ, E.G. (1964). The taxonomy of Polysiphonia in Hawaii. Pacif. Sci. 18(2), 207–222.
REINBOLD, T. (1897). Die Algen der Lacepede und Guichen Bay und deren náherer Umgebung (Slid Australien), gesammelt von Dr. A. Engelhart-Kingston. Nuova Notarisia 8, 41–62.
SILVA, P.C., BASSON, P.W. & MOE, R.L. (1996). Catalogue of the Benthic Marine Algae of the Indian Ocean. (Univ. California Press: Berkeley.)
SONDER, O.W. (1853). Plantae Muellerianae. Algae. Linnaea 25, 657–709.
SONDER, O.W. (1855). Algae annis 1852 et 1853 collectae. Linnaea 26, 506–528.
SONDER, O.W. (1880). In Mueller, F., Fragmenta Phytographiae Australiae. Supplementum ad volumen undecinum: Algae Australianae hactenus cognitae, pp. 1–42, 105–107. (Melbourne.)
TISDALL, H.T. (1898). The algae of Victoria. Rep. 7th Meet. Aust. Ass. Adv. Sci., Sydney, 1898, pp. 493–516.
WILSON, J.B. (1892). Catalogue of algae collected at or near Port Phillip Heads and Western Port. Proc. R. Soc. Viet. 4, 157–190.
WOMERSLEY, H.B.S. (1956). The marine algae of Kangaroo Island 1V. The algal ecology of American River inlet. Aust. J. Mar. Freshw. Res. 7, 64–87, Plates 1–7.
WOMERSLEY, H.B.S. (1979). Southern Australian species of Polysiphonia Greville (Rhodophyta). Aust. J. Bot. 27, 459–528.
YENDO, K. (1916b). Notes on Algae new to Japan V. Bat. Mag., Tokyo 30, 243–263.
YOSHIDA, T. (1998). Marine Algae of Japan. (Uchida Rokakuho Publ. Co.: Tokyo.)
ZANARDINI, J. (1874). Phyceae Australicae novae vel minus cognitae. Flora 57, 486–490, 497–505.
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. 80 D–G.
Figure 80 enlarge
Fig. 80. A–C. Polysiphonia amphibolis (AD, A32838). A. Branches with cystocarps. B. Spermatangial branches. C. Tetrasporangial branches. D–G. Polysiphonia mollis (AD, A32929). D. Habit. E. Branches with cystocarps. F. Spermatangial branches. G. Tetrasporangial branches. (All as in Womersley 1979, courtesy of Aust. J. Bot.)
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