Electronic Flora of South Australia Family Fact Sheet
Phylum Phaeophyta – Order Fucales
Thallus usually 10 cm-2 m long, with one to a few simple, terete to compressed, stipes (main axes), bearing radially, distichously or tristichously, primary branches with straight to flexuous axes, usually much branched (especially above when fertile) with more or less determinate, simple or branched, filiform, leaf-like, or obconical laterals; holdfast discoid-conical. Vescicles usually present, subspherical and axillary or replacing ramuli of laterals, or within the ramuli. Growth from a single, three-sided, apical cell in an apical depression. Structure with medulla, cortex, and surface meristoderm in axes and larger branches.
Reproduction: Thalli monoecious or dioecious. Receptacles usually developed seasonally on upper parts of primary branches, in axils of laterals or their ramuli, simple or in branched clusters, terete to compressed, smooth, verrucose or spinous. Conceptacles and their ostioles usually scattered, unisexual or bisexual; oogonia sessile, with a single egg; antheridia sessile or on branched paraphyses.
Taxonomic notes: A family of some seven genera, with Sargassum (150–200 species) widely distributed in tropical to cool temperate seas, Turbinaria Lamouroux (about 15 species) in tropical-subtropical waters, Carpophyllum Greville (four species) in New Zealand, Hizikia Okamura (one species) in Japan, Acystis Schiffner (one species) in the Arabian Sea, and Anthophycus Kützing and Oerstedtia Trevisan in South Africa.
The Sargassaceae are characterised by the presence of receptacles in the axils of laterals or ramuli, formed as separate branch systems and not transformed from vegetative ramuli.
References: The Marine Benthic Flora of Southern Australia Part II
Womersley, H.B.S. (14 December, 1987)
The Marine Benthic Flora of Southern Australia
©Board of the Botanic Gardens and State Herbarium, Government of South Australia
State Herbarium of South Australia