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Electronic Flora of South Australia Genus Fact Sheet
Phylum Rhodophyta – Class Florideophyceae – Order Gigartinales – Family Acrotylaceae
Thallus erect, much branched irregularly, branches slender, terete, apices pointed to rounded; holdfast fibrous. Structure uniaxial, with the axial cells each bearing two periaxial cells on adjacent radii and rotated about the axis on successive axial cells, the axial filament soon inconspicuous and with a broad, lax, filamentous medulla and narrow pseudoparenchymatous cortex 2–3 cells thick, with large inner cells and small outer cells forming rosettes in surface view.
Reproduction: Sexual thalli monoecious; procarpic; monocarpogonial. Carpogonial branches 3-celled, borne on inner cortical cells, directed inwards with reflexed trichogynes. Supporting cell becoming the auxiliary cell, producing several gonimoblast initials towards the thick mass of inward nutritive filaments, then with gonimoblast filaments spreading around cavity due to breakdown of auxiliary and adjacent cells and forming centripetal filaments with single terminal carposporangia. Cystocarps embedded, with filamentous enveloping tissue and a cortical ostiole. Spermatangial initials in scattered groups in outer cortex, each bearing 2–3 spermatangia.
Tetrasporangia in outer cortex, laterally pit-connected, zonately divided.
Life history triphasic with isomorphic gametophytes and tetrasporophytes.
Type (and only) species: A. nigrescens (Harvey in Hooker & Harvey)Kraft & Min-Thein 1983: 177.
Taxonomic notes: Antrocentrum differs from all other genera of the Acrotylaceae in being uniaxial, but the mature thallus structure and reproduction are typical of the family.
References:
KRAFT, G.T. & MIN-THEIN, U. (1983). Claviclonium and Antrocentrum, two new genera of Acrotylaceae (Gigartinales, Rhodophyta) from southern Australia. Phycologia 22, 171–183.
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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