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Electronic Flora of South Australia Genus Fact Sheet
Phylum Rhodophyta – Class Florideophyceae – Order Gigartinales – Family Halymeniaceae
Thallus much branched irregularly radially for 2–4 orders, branches terete, slender, tapering; holdfast discoid, with one to several fronds. Structure multiaxial, from a group of discrete apical cells with the subapical cells producing single periaxial cells in orthostichous rows, developing a cortex 3–4 cells thick, the inner cells ovoid, not becoming stellate, and a lax medulla of irregularly orientated filaments with outer stellate cells; refractive ganglionic cells absent.
Reproduction: Sexual thalli dioecious. Carpogonial branches borne on inner cortical cells, 4-celled, the subhypogynous cell largest, without ampullary filaments; connecting filaments robust, arising from the carpogonium. Auxiliary cell ampullae simple, with 4–5 secondary filaments, cupulate. Carposporophyte with basal auxiliary cell and slight involucre from ampullary filaments with enlarged cells; ostioles present. Spermatangia cut off from outer cortical cells.
Tetrasporangia scattered in the cortex, cruciately divided.
Life history triphasic with isomorphic gametophytes and tetrasporophytes.
Type species: Z. chondriopsidea (J. Agardh)Lewis & Kraft 1992: 286.
Taxonomic notes: Zymurgia has auxiliary cell ampullae typical of the Halymeniaceae but differs from most other genera of the family in the absence of ampullae around the carpogonial branches. The form of the carpogonial branch, with its large subhypogynous cell, and the unusual thallus apex, make the genus unique in the family.
References:
LEWIS, J.A. & KRAFT, G.T. (1992). Zymurgia, a new genus of Halymeniaceae (Gigartinales, Rhodophyta) from south-eastern Australia. Phycologia 31, 285–299.
The Marine Benthic Flora of Southern Australia Part IIIA complete list of references.
Publication:
Womersley, H.B.S. (14 January, 1994)
The Marine Benthic Flora of Southern Australia
Rhodophyta. Part IIIA, Bangiophyceae and Florideophyceae (to Gigartinales)
Reproduced with permission from The Marine Benthic Flora of Southern Australia Part IIIA 1994, by H.B.S. Womersley. Australian Biological Resources Study, Canberra. Copyright Commonwealth of Australia.
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