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Electronic Flora of South Australia Family Fact Sheet
Phylum Rhodophyta – Class Florideophyceae – Order Corallinales
Thallus mostly calcified, encrusting to warty, lumpy or fruticose; epigenous and partially to completely affixed by cell adhesion, or growing unattached and free-living as rhodoliths; non-geniculate. Structure pseudoparenchymatous; organisation dorsiventral in crustose portions but radial in protuberant branches; construction monomerous, consisting of a single system of branched, laterally cohering, filaments that collectively contribute to a ventrally or centrally situated core and a peripheral region where portions of core filaments or their derivatives curve outwards towards the thallus surface; walls of most vegetative cells impregnated with calcite; cells of adjacent filaments joined laterally by both fusions and secondary pit-connections but proportions varying within and between species; epithallial cells terminating most filaments at thallus surface, distal walls commonly uncalcified; haustoria unknown.
Reproduction: Vegetative reproduction by thallus fragmentation. Gametangia and carposporangia borne in uniporate conceptacles; tetrasporangia borne in calcified compartments that may be solitary or aggregated into sori and are derived from the walls of tetrasporangial initials; gametangia and carposporangia normally formed on separate thalli from tetrasporangia. Reports of bisporangia unconfirmed.
Gametangial thalli monoecious or dioecious; carpogonia and spermatangia produced in separate conceptacles or rarely in the same conceptacle. Carpogonial filaments usually 1 to 4-celled, arising from the female conceptacle chamber floor and in some species also from the walls. Carposporophytes developing within female conceptacles after karyogamy, carposporangia either developing more or less directly from the fertilized carpogonium or terminating short gonimoblast filaments that usually arise from an inconspicuous fusion cell. Spermatangial filaments branched, restricted to the male conceptacle chamber floor or borne on the floor, walls and roof.
Tetrasporangia formed within calcified compartments that may be solitary or more usually aggregated into sori of irregular shape and indefinite size, compartments interspersed amongst vegetative filaments or enclosed in sporangial complexes; each mature sporangium containing four cruciately arranged tetraspores and possessing an apical plug that blocks the compartmental pore prior to spore release.
Life history triphasic with isomorphic gametangial and tetrasporangial generations and a heteromorphic carposporangial generation.
Type genus: Sporolithon Heydrich 1897a: 66.
Taxonomic notes: The Sporolithaceae includes a single subfamily, the Sporolithoideae Setchell (1943, p. 134, as `Sporolitheae'), with two genera. Heydrichia (see Townsend et al. 1995) is known only from southern Africa, while Sporolithon is known from various tropical and temperate regions, including southern Australia. Additional information on the Sporolithaceae is provided by Verheij (1993a) and Townsend et al. (1995).
References:
HEYDRICH, F. (1897a). Corallinaceae, inbesondere Melobesieae. Ber. dt. bot. Ges. 15, 34–71, Plate 3.
SETCHELL, W.A. (1943). Mastophora and the Mastophoreae: Genus and subfamily of Corallinaceae. Proc. Nat. Acad. Sci. Washington 29, 127–135.
TOWNSEND, R.A., WOELKERLING, W.J., HARVEY, A.S. & BOROWITZKA, M. (1995). An account of the red algal genus Sporolithon (Sporolithaceae, Corallinales) in southern Australia. Aust. Syst. Bot. 8, 85–121.
VERHEIJ, E. (1993a). The genus Sporolithon (Sporolithaceae fam. nov., Corallinales, Rhodophyta) from the Spermonde Archipelago, Indonesia. Phycologia 32, 184–196.
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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