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Electronic Flora of South Australia Genus Fact Sheet
Phylum Rhodophyta – Class Florideophyceae – Order Corallinales – Family Corallinaceae – Subfamily Austrolithoideae
Thallus largely unconsolidated except in areas of conceptacle production, almost entirely endophytic including conceptacles; genicula absent. Structure partly filamentous and partly pseudoparenchymatous, without apparent dorsiventral, radial or isobilateral organisation; construction diffuse, consisting of branched endophytic filaments that usually become partially consolidated in areas of conceptacle production but collectively lack any regularised internal structure; epithallial cells absent from vegetative portions of thallus but terminating most conceptacle roof filaments, with distal walls rounded or flattened but not flared; cell elongation characteristics uncertain; cell-fusions, secondary pit-connections, haustoria and trichocytes unknown.
Reproduction: Vegetative reproduction unknown. Gametangia and carposporangia borne in largely endophytic uniporate conceptacles; tetrasporangia borne in largely endophytic multiporate conceptacles. Bisporangia unknown.
Gametangial thalli dioecious. Carpogonia terminating 2-celled filaments arising from the female conceptacle chamber floor. Carposporophytes each composed of a central fusion cell and several-celled gonimoblast filaments bearing terminal carposporangia. Spermatangial filaments both unbranched and branched, borne on the floor, walls and roof of each male conceptacle chamber.
Tetrasporangia scattered across the conceptacle chamber floor, roofs formed by filaments interspersed amongst and peripheral to sporangial initials; each mature sporangium containing four zonately arranged tetraspores and possessing an apical plug that blocks a roof pore prior to spore release.
Type species: A. intumescens A. Harvey & Woelkerling 1995: 363.
Taxonomic notes: Austrolithon includes a single known species. This account is based on data in A. Harvey & Woelkerling (1995).
References:
HARVEY, A.S. & WOELKERLING, W.J. (1995). An account of Austrolithon intumescens gen. et sp. nov. and Boreolithon van-heurckii (Heydrich) gen. et comb. nov. (Austrolithoideae subfam. nov., Corallinaceae, Rhodophyta). Phycologia 34, 362–382.
The Marine Benthic Flora of Southern Australia Part IIIB complete list of references.
Publication:
Womersley, H.B.S. (28 June, 1996)
The Marine Benthic Flora of Southern Australia
Rhodophyta. Part IIIB. Gracilarialse, Rhodymeniales, Corallinales and Bonnemaisoniales
Reproduced with permission from The Marine Benthic Flora of Southern Australia Part IIIB 1996, by H.B.S. Womersley. Australian Biological Resources Study, Canberra. Copyright Commonwealth of Australia.
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