Electronic Flora of South Australia Family Fact Sheet


Phylum Chlorophyta

Thallus coenocytic, formed of much branched filaments either associated in tufts or interwoven, or morphologically differentiated into a basal stolon with rhizoids and erect, variously branched fronds; cell walls of microfibrilar xylan; heteroplastic, with chloroplasts and amyloplasts, and the chloroplasts containing siphonein and siphonoxanthin.

Life history diplontic with gametic meiosis, isogamous or (usually) anisogamous.

Taxonomic notes: The Caulerpales were separated from the broader and older "Siphonales" by Feldmann (1946, p. 753; 1955) on the basis of their heteroplasty and wall structure with xylan replacing cellulose. Parker (1970) reviewed the value of wall structure in separating orders of the Chlorophyta. The Caulerpales contain three families, two of which are represented on southern Australian coasts: The Udoteaceae have a thallus of tufted or, more usually, interwoven filaments showing considerable structural similarity to the Codiaceae. The Caulerpaceae are quite different in their structure and morphology, with a distinctive thallus plan and a great variety of frond morphologies which characterise the species.

Some authors (e.g. Bold & Wynne 1978, p. 190) recognise a much broader order Caulerpales, including the families here placed in the Codiales and Derbesiales.


BOLD, H.C. & WYNNE, M.J. (1978). Introduction to the Algae: Structure and reproduction. (Prentice-Hall: New Jersey.)

FELDMANN, J. (1946). Sur l'hétéroplastie de certaines Siphonales et leur classification. C.R. Acad. Sc. Paris 222, 752–753.

FELDMANN, J. (1955). Les plaster des Caulerpa et leur valeur systématique. Rev. Gen. Bet. 62, 1–10.

PARKER, B.C. (1970). Significance of cell wall chemistry to phylogeny in the algae. Ann. N.Y. Acad. Sci. 175, 417–428.

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


1. Thallus composed of tufted, subdichotomous filaments or of filaments interwoven to form a macroscopic, often flattened, usually branched thallus


1. Thallus not of interwoven filaments but differentiated into a horizontal stolon attached by rhizoids and bearing erect, variously branched, fronds; thallus with internal trabeculae traversing the lumen


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