Electronic Flora of South Australia Family Fact Sheet
Phylum Rhodophyta – Class Florideophyceae
Thallus crustose, with or without erect branches, cartilaginous, surface smooth or tuberculate. Structure of a basal layer of laterally adherent, branched, filaments, with each cell producing an erect, laterally coherent filament of small cuboidal cells, and in erect taxa developing a medulla of anastomosing filaments and a cortex of appressed anticlinal filaments; rhizoids absent. Pit-connections primary and secondary, pit-plugs with a single cap layer.
Reproduction: Sexual reproduction unknown.
Tetrasporangia (apomeiotic at least in some taxa) formed in subspherical to urceolate, ostiolate, conceptacles (which enlarge with age), arising from any wall cell, zonately or irregularly divided, with or without paraphyses.
Taxonomic notes: This order is based on the genus Hildenbrandia and was separated by Pueschel & Cole (1982, p. 718) largely on the basis of the single layered pit-plugs; this was re-affirmed by Pueschel (1989, p. 632).
A second genus from New Zealand, Apophloea Harvey (see Hawkes 1983) has similar conceptacles and pit-plugs (Pueschel 1989, p. 632, fig. 15) to Hildenbrandia and is usually placed in the Hildenbrandiaceae and Hildenbrandiales. Its erect, branched habit differs from the crusts of most species of Hildenbrandia, but H. lecannellieri with its tuberculate excrescences has an intermediate form.
HAWKES, M.W. (1983). Anatomy of Apophlaea sinclairii - An enigmatic red alga endemic to New Zealand. Jap. J. Phycol. 31, 55–64.
PUESCHEL, C.M. & COLE, K.M. (1982). Rhodophycean pit plugs: an ultrastructural survey with taxonomic implications. Amer. J. Bot. 69, 703–720.
PUESCHEL, C.M. (1989). An expanded survey of the ultrastructure of red algal pit plugs. J. Phycol. 25, 625–636.
The Marine Benthic Flora of Southern Australia Part IIIA complete list of references.
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.
State Herbarium of South Australia