Electronic Flora of South Australia Family Fact Sheet


Phylum Phaeophyta – Order Desmarestiales

Thallus (sporophyte) large, (20–) 50 cm-2 m(-10 m) long, terete to compressed or foliose, sparingly to much branched pinnately, with trichothallic growth and opposite branching of the apical filaments, becoming densely corticated below, pseudoparenchymatous, developing a large-celled medulla with intermixed hyphae around the axial filament and a small-celled phaeoplastic cortex. Gametophytes microscopic, filamentous, branched, monoecious or dioecious.

Reproduction: Sporophyte with unilocular sporangia scattered in the outer cortex, inconspicuous, or terminating short cortical filaments, or in surface sori, hemispherical or diffuse with cellular paraphyses. Gametophytes oogamous.

Taxonomic notes: A family of three genera: Desmarestia, essentially of cold temperate distribution, and two genera (Himantothallus and Phaeurus) from Antarctic and Subantarctic waters, where they can be dominant.

References: The Marine Benthic Flora of Southern Australia Part II

Author: H.B.S. Womersley

Publication: Womersley, H.B.S. (14 December, 1987)
The Marine Benthic Flora of Southern Australia
Part II
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