Electronic Flora of South Australia Species Fact Sheet

Chordaria cladosiphon Kützing 1859: 2, pl. 2 fig. II.

Phylum Phaeophyta – Order Chordariales – Family Chordariaceae

Selected citations: Nelson & Adams 1983: 84, figs 7,8. Bailey & Womersley in Womersley 1967: 232.


Cladosiphon chordaria Harvey 1858: pl. 60; 1859b: 292.

Cladosiphon chordaria var. dictyosiphon Harvey 1858: pl. 60.

Chordaria dictyosiphon (Harvey) Kützing 1859: 2, pl. 2 fig. I. Kylin 1940: 40, fig. 21C. Lindauer et al. 1961: 231, fig. 53.

Thallus (Fig. 35A) dark brown, not or slightly mucoid, irregularly branched with one to a few main axes bearing long, slightly to much branched laterals, usually 6–20 (–25) cm long with branches cylindrical and 0.5–1.5 (–2) mm in diameter, tapering to base and apex. Medulla (Fig. 36A,B) multiaxial, with an outer medulla of closely associated, cylindrical, longitudinal filaments, 8–16 µm in diameter with cells L/B 8–20, and an inner medulla of loose, irregularly orientated, slender filaments 6–12 um in diameter with cells L/B 5–12, and which becomes largely hollow. Cortical filaments (Fig. 36B–D) arising directly from shorter (L/B 1–2) peripheral medullary cells, 1–4 per cell, simple or once branched from their basal cell, clavate, 40–60 µm and 2–3 cells long with the terminal cell 6–10 µm in diameter near its upper end and L/B 2–4 (–5). Phaeoplasts (Fig. 36D) few per cell, discoid to elongate; physodes present. Phaeophycean hairs (Fig. 36B) scattered, arising from outer medullary cells, 10–12(4 4) µm in diameter.

Reproduction: Plurilocular sporangia(?) (Fig. 36E) borne on outer medullary cells, simple or branched, uniseriate, 20–30 µm and 4–6 locules long, 4–6 µm in diameter, with a unicellular pedicel. Unilocular sporangia (Fig. 36B,C,E) sessile on outer medullary cells, clavate to elongate ovoid, 25–35 µm long and 8–12 µm in diameter.

Lectotype from Brighton, Port Phillip, Vic. (Harvey, Alg. Aust. Exsicc. 95); in Herb. Sonder, MEL, 8609. Isotypes in TCD and other herbaria.

Selected specimens: Bridgewater Bay, Vic., lower eulittoral (Womersley, 25.i.1967; ADU, A31772). Apollo Bay, Vic., lower eulittoral ( Womersley, 26.i.1964 and 23.i.1967; ADU, A28052 and A31751-"Marine Algae of southern Australia" No. 43a). Lorne, Vic., lower eulittoral pools ( Womersley, 23.i.1967; ADU, A31531-"Marine Algae of southern Australia" No. 43b). Flinders, Vic., lower eulittoral (Bailey, 27.i.1967; ADU, A30911). Walkerville, Vic., uppermost sublittoral (Sinkora A2388, 23.ii.1978; ADU, A53579). Guyton Point, Robbins I., Tas., lower eulittoral (Wollaston & Mitchell, 23.ii.1964; ADU, A27614). Low Head, Tas. (Perrin, June 1940; ADU, A54793). Port Arthur, Tas. (Cribb 37.1, 6.iii.1950; ADU, A16021).

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

Distribution: From Bridgewater Bay to Walkerville, Vic. and around Tasmania. New Zealand (South I., Stewart I., Chatham Is).

Taxonomic notes: Uncertainty regarding Kützing's (1859, pl. 2 fig. I) illustration of Chordaria dictyosiphon was expressed previously (Bailey & Womersley in Womersley 1967, p. 232), with regard to the cortical assimilatory filaments. It seems likely that Kützing's illustration was of the same structures described by Kylin (1940, p. 40, fig. 21C) as plurilocular sporangia, but which have not been established from live material as being sporangia; they are also similar to very young hairs, but the latter do not branch basally as often as do the "plurilocular sporangia".


HARVEY, W.H. (1858). Phycologia Australica. Vol. I, Plates 1–60. (Reeve: London.)

HARVEY, W.H. (1859b). Algae. In Hooker, J.D., The Botany of the Antarctic Voyage. Part III. Flora Tasmaniae. Vol. 2, pp. 282–343, Plates 185–196.

KÜTZING, F.T. (1859). Tabulae Phycologicae. Vol. 9. (Nordhausen.)

KYLIN, H. (1940). Die Phaeophyceenordnung Chordariales. Acta Univ. lund. N.F. Avd. 2, 36(9), 1–67, Plates 1–8.

LINDAUER, V.W., CHAPMAN, V.J. & AIKEN, M. (1961). The marine algae of New Zealand. II. Phaeophyceae. Nova Hedwigia 3, 129–350, Plates 57–97.

NELSON, W.A. & ADAMS, N.M. (1983). A taxonomic revision of the families Chordariaceae and Chordariopsidaceae (Phaeophyta) in New Zealand. N.Z. J. Bot. 21, 77–92.

WOMERSLEY, H.B.S. (1967). A critical survey of the marine algae of southern Australia. II. Phaeophyta. Aust. J. Bot. 15, 189–270.

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

Author: H.B.S. Womersley & A. Bailey

Publication: Womersley, H.B.S. (14 December, 1987)
The Marine Benthic Flora of Southern Australia
Part II
©Board of the Botanic Gardens and State Herbarium, Government of South Australia

Illustrations in Womersley Part II, 1997: FIGS 35A, 36 A–E.

Figure 35 image

Figure 35   enlarge

Fig. 35. A. Chordaria cladosiphon (ADU, A31751). B. Cladosiphon filum (ADU, A51867). C. Cladosiphon vermicularis (ADU, A30919). D. Polycerea nigrescens (ADU, A51868). E. Polycerea zostericola (ADU, A56954).

Figure 36 image

Figure 36   enlarge

Fig. 36. A–E. Chordaria cladosiphon (A–C, ADU, A28052; E, ADU, 27614). A. Longitudinal section of apex, showing subapical development, medulla and cortex. B. Transverse section (partly diagrammatic) showing outer and inner medulla, and cortex of 2-3 celled filaments with unilocular sporangia and phaeophycean hairs. C. Longitudinal section showing medulla and cortex with assimilatory filaments, unilocular sporangia and phaeophycean hairs. D. Cortical filaments with phaeoplasts. E. Plurilocular (and a unilocular) sporangia within the cortex. F,G. Cladosiphon ilium (ADU, A51867). F. Transverse section showing medullary cells, short subcortex, determinate cortical filaments with plurilocular sporangia above, and two phaeophycean hairs. G. Upper part of a determinate cortical filament with plurilocular sporangial clusters and cells with phaeoplasts and physodes.

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