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Electronic Flora of South Australia Family Fact Sheet
Phylum Rhodophyta
Thallus unicellular or more usually multicellular, forming simple or branched uniseriate or multiseriate filaments, or monostromatic or polystromatic discs or cushions, or monostromatic or distromatic foliose blades; growth diffuse, rarely apical; cells uninucleate, in most genera with a single stellate rhodoplast usually with a central pyrenoid, in some genera with parietal, discoid to lobed rhodoplasts with or without a pyrenoid. Pit-connections absent except in the conchocelis (or pseudoconchocelis) phase.
Reproduction: Reproduction in simpler genera usually by monospores formed from whole vegetative cells or in sporangia cut off by a curved wall; sexual reproduction absent or unverified in most simpler genera. In morphologically larger taxa of the Bangiales, sexual reproduction common, with carpogonia formed from vegetative cells, and spermatangia by subdivision of vegetative cells to give 64–256 spermatia. The zygote divides directly into 4–16 (–32) carposporangia which on liberation form the microscopic conchocelis phase which reproduces itself by monospores and undergoes meiosis in fertile cell rows, the meiospores producing the gametophytic macrothalli again.
Life history monophasic or biphasic.
Taxonomic notes: The class Bangiophyceae is distinguished by the lack of pit-connections (except in the conchocelis phase), diffuse growth of the thallus, and by simple reproduction with only the larger advanced members showing well-developed sexual reproduction with simple carpogonia and direct division of the zygote into carposporangia.
The Bangiophyceae have been reviewed by Drew (1956b), Dixon (1973), Garbary et al. (1980a), Cole & Conway (1980) and Magne (1989). The classification used below is based on that of Garbary et al. (1980a), but using the older order name Compsopogonales in preference to their Erythropeltidales. Magne (1989) places the Porphyridiales in his subclass Archaeorhodophycidae (which lacks spores or "true cysts"), the Compsopogonales (and Erythropeltidales) in his Metarhodophycidae (with formation of reproductive cells from part of the parent cell) and the Bangiales and all higher orders in his Eurhodophycidae (with the whole parent cell producing reproductive bodies). Norris (1992b, p. 3) elevates these subclasses to classes.
References:
COLE, K. & CONWAY, E. (1980). Studies in the Bangiaceae: Reproductive modes. Bot. Mar. 23, 545–553.
DIXON, P.S. (1973). Biology of the Rhodophyta. Univ. Reviews in Botany, Vol. 4. (Oliver & Boyd: Edinburgh.)
DREW, K.M. (1956b). Reproduction in the Bangiophycidae. Bot. Rev. 22, 553–611.
GARBARY, D.J., HANSEN, G.I. & SCAGEL, R.F. (1980a). A revised classification of the Bangiophyceae (Rhodophyta). Nova Hedwigia 33, 145–166.
MAGNE, F. (1989). Classification et phylogénie des Rhodophycées. Cryptogamie, Algol. 10, 101–115.
NORRIS, R.E. (1992b). The marine red algae of Natal, South Africa: Order Gélidiales (Rhodophyta). Mem. Bot. Survey South Africa No. 61.
WETTSTEIN, A. (1901). Handbuch der systematischen Botanik. (Leipzig & Vienna.)
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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