Electronic Flora of South Australia Species Fact Sheet

Pseudochlorodesmis australis (Womersley) Womersley, comb. nov.

Phylum Chlorophyta – Order Caulerpales – Family Udoteaceae


Chlorodesmis australis Womersley 1955: 388, fig. 3.

Thallus (Fig. 81A) medium to dark green, 0.5–1.5 cm high, forming loose tufts, branching only at the base with 2–4 dichotomies close together, attached by rhizoids. Filaments (Fig. 82A) constricted immediately above each dichotomy, above linear, 25–45 (–60) µm in diameter; cell wall thin, slightly thickened at basal constrictions (Fig. 82B); chloroplasts dense, round to ovoid, 1.5–3.0 Aim across; amyloplasts probably present.

Reproduction: Reproduction unknown.

Type from Robe, S. Aust. ( Womersley, 28.vii.1949); in ADU, A12250.

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

Distribution: Known from the type and from Vivonne Bay, Kangaroo I., S. Aust., in shaded pool, S. side of Ellen Point ( Womersley, 22.xi.1968; ADU, A32887). Pennington Bay, Kangaroo I., S. Aust., in shaded pool (Womersley, 4.i.1948, ADU, A53380 ). Robe, S. Aust., lower eulittoral in sand, slipway reef (Womersley, 24.viii.1960; ADU, A24431).

Taxonomic notes: This species needs further investigation but seems best referred to Pseudochlorodesmis rather than Chlorodesmis which has much broader and frequently branched and constricted filaments. It differs from P. furcellata in dimensions and lack of upper branching and from P. parva Gilbert (1962, p. 141) and P. tenuis Ercegovic (1957, p. 33) in lack of upper branching.


ERCEGOVIC, A. (1957). La flore sous-marine de l'îlot de Jabuka. Acta Adriatica 8(8), 1–130.

GILBERT, W.J. (1962). Contributions to the marine Chlorophyta of Hawaii I. Pac. Sci. 16, 135–144.

WOMERSLEY, H.B.S. (1955). New marine Chlorophyta from southern Australia. Pacif. Sci. 9, 387–395.

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

Illustrations in Womersley Part I, 1984: FIGS 81A, 82A,B.

Figure 81 image

Figure 81   enlarge

Fig. 81. A. Pseudochlorodesmis australis (ADU, Al2250, type). B. Chlorodesmis baculifera (ADU. A51906. right hand specimen fertile). C. Halimeda cuneata (ADU. A50610). D. Pseudocodium australasicum(ADU. A 13618, type).

Figure 82 image

Figure 82   enlarge

Fig. 82. A,B. Pseudochlorodesmis australis (ADU, Al2250, type). A. A tuft of filaments. B. Detail of basal dichotomies. C,D. Chlorodesmis baculifera (ADU, A51906). C. Part of filament showing branching. D. Fertile filaments with zooidangia. E–G. Halimeda cuneata (ADU, A50610). E. Surface view of cortical cells. F. Peripheral, secondary and tertiary utricles. G. Nodal organisation, with filaments united in groups at base of node.

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