Electronic Flora of South Australia Species Fact Sheet

Rhizoclonium riparium (Roth) Harvey 1849: pl. 238.

Phylum Chlorophyta – Order Cladophorales – Family Cladophoraceae

Selected citations: Abbott & Hollenberg 1976: 92, fig. 46. Bliding 1957: 274, fig. 3. Davey & Woelkerling 1980: 57. Kornmann & Sahling 1977: 47, fig. 18A–F. Koster 1955: 335, fig. 1. Nienhuis 1974: 172. Scagel 1966: 74, pl. 32A–E.

Thallus light to medium green, forming thin mats or strands of entangled filaments to 5 (–10) cm long in eulittoral, usually shaded, calm water habitats (e.g on sandy mud or mangroves). Filaments (Fig. 53D) simple, irregularly curved or twisted, with occasional to fairly frequent lateral rhizoids of 1–2 (–5) cells, irregularly placed. Cells 16–22 µm in diameter, L/B 1–1.5 (–2), wall about 2 µm thick, 1–4 nuclei per cell; chloroplast densely reticulate with several pyrenoids.

Reproduction: Reproduction not reported for Australian plants. Elsewhere by biflagellate isogametes and quadriflagellate or biflagellate zoospores (Nienhuis 1974).

Type from Norderney, Germany (Mertens); holotype destroyed but lectotype in BM (ex K) (see Koster 1955, p. 336).

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

Distribution: Cosmopolitan.

In southern Australia known from Proper Bay, Port Lincoln, S. Aust. upper eulittoral, shaded (Womersley, 7.i.1951; ADU, A15065). Port Clinton, S. Aust., mid eulittoral on A vicennia pneumatophores (Womersley, 18.ix.1981; ADU, A52913). Pelican Lagoon, American R. inlet, Kangaroo I., S. Aust., upper eulittoral in shade (Womersley, 19.i.1950; ADU, A12923). Long Bay, Port Arthur, Tas., upper eulittoral (Cribb, 22.i.1951; ADU, A16012). Probably fairly general in sheltered habitats along the coast. Beanland & Woelkerling (1982, p. 100) have recorded R. riparium from numerous localities in Spencer Gulf, S. Aust., but their range of filament diameters is considerably greater than accepted here.


ABBOTT, I.A. & HOLLENBERG, G.J. (1976). Marine Algae of California. (Stanford Univ. Press: Stanford.)

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

BLIDING, C. (1957). Studies in Rhizoclonium. I. Life history of two species. Bot. Notiser 110, 271–275.

DAVEY, A. & WOELKERLING, W.J. (1980). Studies on Australian mangrove algae. 1. Victorian communities: Composition and geographic distribution. Proc. R. Soc. Vict. 91, 53–66.

HARVEY, W.H. (1849). Phycologia Britannica. Plates 217–252 (Reeve: London.)

KORNMANN, P. & SAHLING, P.-H. (1977). Meeresalgen von Helgoländ. Benthische Grun-Braun-und Rotalgen. Helgoländer wiss. Meeresunters. 29, 1–292.

KOSTER, J.Th. (1955). The genus Rhizoclonium Kutz. in the Netherlands. Pubbl. Staz. Zool. Napoli. 27, 335–357.

NIENHUIS, P.H. (1974). Variability in the life cycle of Rhizoclonium riparium (Roth) Harv. (Chlorophyceae: Cladophorales) under Dutch estuarine conditions. Hydrobiol. Bull. 8, 172–178.

SCAGEL, R.F. (1966). Marine algae of British Columbia and Northern Washington, Part I: Chlorophyceae (Green Algae). Natl Mus. Can. Bull. 207, i-viii, 1–257.

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

Author: H.B.S. Womersley

Publication: Womersley, H.B.S. (31 May, 1984)
The Marine Benthic Flora of Southern Australia
Part I
©Board of the Botanic Gardens and State Herbarium, Government of South Australia

Illustration in Womersley Part I, 1984: FIG. 53D.

Figure 53 image

Figure 53   enlarge

Fig. 53. A. Rhizoclonium implexum (ADU, A52995). B,C. Rhizoclonium tortuosum. B. Filament with rhizoidal branch (ADU, A15398). C. Filament (ADU, A52994). D. Rhizoclonium riparium (ADU, A52913). E,F. Rhizoclonium curvatum (ADU, A52647). E. Arcuate filament with rhizoids. F. Part of filament with rhizoid.

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