Electronic Flora of South Australia Family Fact Sheet
Thallus of branched filaments of cells, heterotrichous with distinct prostrate basal and erect branch systems but in some genera with either system strongly reduced and in some taxa with unicellular or multicellular colourless hairs. Cells small, uninuncleate; chloroplast single, parietal, often band-shaped or lobed and not occupying all the cell wall, usually with one to a few pyrenoids.
Reproduction: Reproduction by isogametes, anisogametes or oogametes and by biflagellate or quadriflagellate zoospores.
Life history inadequately known, but haplontic and diplohaplontic types apparently occur.
Taxonomic notes: This order, which has frequently been placed as a family of the Ulotrichales, consists (in the marine environment) mostly of small epiphytes characterised by branched filaments showing distinct heterotrichy. Only two genera have been recorded for southern Australian coasts but others certainly occur, including some shell-boring taxa. The better known marine flora of Britain (Parke & Dixon 1976) includes 16 genera and 23 species, and that of California (Abbott & Hollenberg 1976) 8 genera and 12 species of Chaetophorales.
The two genera so far recorded from southern Australian coasts are placed in separate families, of which the second (Chroolepidaceae) appears to be inadequately characterised.
ABBOTT, I.A. & HOLLENBERG, G.J. (1976). Marine Algae of California. (Stanford Univ. Press: Stanford.)
PARKE, M. & DIXON, P.S. (1976). Check-list of British marine algae-third revision. J. mar. biol. Ass. U.K. 56, 527–594.
The Marine Benthic Flora of Southern Australia Part I complete list of references.
Womersley, H.B.S. (31 May, 1984)
The Marine Benthic Flora of Southern Australia
©Board of the Botanic Gardens and State Herbarium, Government of South Australia
KEY TO FAMILIES OF CHAETOPHORALES
1. Colour green; thallus often reduced to the basal prostrate system only, with or without hairs; reproduction from vegetative cells
1. Colour yellow-green (or red) due to an excess of carotenoid pigments; thallus distinctly heterotrichous, without hairs; reproductive organs differentiated cells
State Herbarium of South Australia