Electronic Flora of South Australia Genus Fact Sheet

Genus CLADOSTEPHUS C. Agardh 1817: xxv

Phylum Phaeophyta – Order Sphacelariales – Family Cladostephaceae

Thallus 5–25 cm long, with one to several subdichotomous axes from the crustose base. epilithic. Branching of axes and indeterminate laterals hypacroblastic, with the superior of the two secondary segments producing a whorl of determinate laterals, which may remain verticillate or become densely crowded along the axes ("spongiosus" form); axial segments subdividing both transversely and longitudinally and undergoing secondary growth, with a dense parenchymatous cortex developing and surrounding the determinate laterals. Determinate laterals 1–3 mm long, with I to a few laterals developed acroblastically and bearing hairs in their axils.

Reproduction: Reproduction by pedicellate unilocular sporangia and plurilocular gametangia (isogamous) borne laterally on lateral ramuli densely clustered on older parts of indeterminate axes, developed from outer cortical cells.

Lectotype species: C. spongiosus (Hudson) C. Agardh.

Taxonomic notes: A genus of 1 to a few (?) species (Sauvageau 1914. pp. 601–604) with C. verticillatus being considered synonymous with C. spongiosus.

References:

AGARDH, C.A. (1817). Synopsis Algarum Scandinaviae. (Lund.)

The Marine Benthic Flora of Southern Australia Part II complete list of references.

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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