|
|
|
|
|
|||||||||||
|
Electronic Flora of South Australia Family Fact Sheet
Phylum Rhodophyta – Order Ceramiales – Family Ceramiaceae
Thallus erect, pinnate and complanately branched with irregularly alternate indeterminate branches bearing short, close set, distichous, determinate branchlets. Apical cells dividing obliquely, with either 4 spirally developed periaxial cells (filaments), the first formed becoming alternately distichous determinate branchlets, the second and third formed becoming caducous, and the fourth contributing only to the cortex (Rhodocallis), or with 2 lateral and 2–4 transverse (on each side) filaments (Psilothallia), with the lateral ones forming alternate distichous determinate branchlets. Indeterminate branches becoming densely corticated, and with dense rhizoidal filaments (appearing pseudoparenchymatous) around the axial cells. Gland cells absent. Cells uninucleate.
Reproduction: Gametophytes dioecious. Procarps borne on periaxial filaments, with the periaxial cell acting as supporting cell with a 4-celled carpogonial branch. Auxiliary cell dividing to form a foot cell and gonimoblast initial usually producing several gonimolobes, with or without a rhizoidal involucre from the basal cell of the sterile branchlet on the fertile axial cell and an outer involucre of determinate branchlets or simple filaments. Spermatangia cut off from initials on the surface cortical cells.
Tetrasporangia derived directly from surface cortical cells of the determinate branchlets, or on branched filaments or in siliculose branchlets on the determinate branchlets.
Life history triphasic with isomorphic gametophytes and tetrasporophytes.
Type genus: Rhodocallis Kützing 1847: 36.
Taxonomic notes: The tribe includes a second genus, Psilothallia Schmitz, though details of its apical development await clarification.
The above description is based on that of Hommersand et al. (1998), modified to cover the characteristics of Psilothallia as far as they are known. The tribe Rhodocallideae was presaged by Wilson, Hommersand & Kraft (1996).
References:
HOMMERSAND, M.H., WILSON, S.M. & KRAFT, G.T. (1998). Morphology and systematics of Rhodocallis elegans Kützing, Rhodocallideae, Trib. nov. (Ceramiaceae, Rhodophyta) from southeastern Australia. J. Phycol. 34, 865–879.
HOMMERSAND, M.H., WILSON, S.M. & KRAFT, G.T. (1998). Morphology and systematics of Rhodocallis elegans Kützing, Rhodocallideae, Trib. nov. (Ceramiaceae, Rhodophyta) from southeastern Australia. J. Phycol. 34, 865–879.
KÜTZING, F.T. (1847). Diagnosen and Bemerkungen zu neuen oder kritischen Algen. Bot. Zeit. 5, 1–5, 22–25, 33–38, 52–55, 164–167, 177–180, 193–198, 219–223.
WILSON, S.M., HOMMERSAND, M.H. & KRAFT, G.T. (1996). The Rhodocallieae: a new tribe in the Ceramiaceae for the Australian-endemic genus Rhodocallis. J. Phycology 32(3), Suppl., p. 51.
The Marine Benthic Flora of Southern Australia Part IIIC complete list of references.
Publication:
Womersley, H.B.S. (24 December, 1998)
The Marine Benthic Flora of Southern Australia
Rhodophyta. Part IIIC. Ceramiales – Ceramiaceae, Dasyaceae
©State Herbarium of South Australia, Government of South Australia
KEY TO GENERA OF RHODOCALLIDEAE
|
1. Apices with 4 periaxial cells and filaments, formed spirally, determinate branchlets alternate on successive axial cells, with terminal and marginal spines. Tetrasporangia formed directly from surface cortical cells in sori | RHODOCALLIS |
|
1. Apices with | PSILOTHALLIA |
|
Email Contact: State Herbarium of South Australia |
|
