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Electronic Flora of South Australia Genus Fact Sheet
Phylum Rhodophyta – Class Florideophyceae – Order Corallinales – Family Corallinaceae – Subfamily Mastophoroideae
Thallus partly to largely unconsolidated; vegetative portions endophytic but conceptacles produced externally to the host; genicula absent. Structure filamentous to partly pseudoparenchymatous, without apparent dorsiventral, radial or isobilateral organisation; construction diffuse, consisting of branched endophytic filaments that may become partially consolidated but collectively lack any regularised internal structure; cell elongation characteristics uncertain; cells of adjacent filaments joined by cell-fusions, secondary pit-connections absent; epithallial cells absent from vegetative portions of thallus but terminating most conceptacle roof filaments, with distal walls rounded or flattened but not flared; haustoria occasional, penetrating cells of host; trichocytes unknown.
Reproduction: Vegetative reproduction unknown. Gametangia, carposporangia and tetrasporangia borne in uniporate conceptacles produced externally to the host. Bisporangia unknown.
Gametangial thalli presumably dioecious. Carpogonia terminating 2- or 3-celled filaments arising from the female conceptacle chamber floor. Carposporophytes arising within female conceptacles after karyogamy; composed of a conspicuous central fusion cell and several-celled gonimoblast filaments bearing terminal carposporangia. Spermatangial filaments unbranched, produced on the floor of male conceptacle chambers.
Tetrasporangia formed peripheral to a central columella, roofs formed only by filaments peripheral to sporangial initials, each mature sporangium lacking an apical plug and containing four zonately arranged tetraspores.
Type species: L. minderiana Woelkerling & Ducker 1987: 193.
Taxonomic notes: Lesueuria contains one known species reported only from southern Australia. The following account is based mainly on data in Woelkerling & Ducker (1987).
References:
WOELKERLING, W.J. & DUCKER, S.C. (1987). Lesueuria minderiana gen. et sp. nov. (Corallinaceae, Rhodophyta) from southern and Western Australia. Phycologia 26, 192–204.
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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