Electronic Flora of South Australia Genus Fact Sheet

Genus HALIMEDA Lamouroux 1812: 186

Phylum Chlorophyta – Order Caulerpales – Family Udoteaceae

Thallus erect or flaccid, arising from a rhizoidal holdfast, moderately to much branched, with the branches consisting of a series of calcified internodes or segments connected by small, uncalcified, flexible nodes; segments usually compressed to flat, in some species cylindrical, discoid or cuneate to reniform. Structure of slender filaments, with a multiaxial core of medullary filaments surrounded by a cortex of layers of utricles, with the walls of the peripheral utricles usually adherent; the nodal medullary filaments remain separate, anastomose in small groups, or unite into a large plate unit.

Reproduction: Reproduction by biflagellate gametes formed in globular to pyriform, stalked, gametangia arising from the segment margin or surface.

Lectotype species: H. tuna (Ellis & Solander) Lamouroux.

Taxonomic notes: A genus of some 30 species (Hillis-Colinvaux 1980), largely confined to tropical-subtropical seas, with one species extending from the west coast into southern Australia.


HILLIS-COLINVAUX, L. (1980). Ecology and taxonomy of Halimeda: Primary producer of coral reefs. Adv. Mar. Biol. 17, 1–327.

LAMOUROUX, J.V.F. (1812). Sur la classification des Polypiers coralligènes non entièrement pierreux. Nouv. Bull. Sci. Soc. Philom. Paris 3, 181–188.

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
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