|
|
|
|
|
|||||||||||
|
Electronic Flora of South Australia Genus Fact Sheet
Phylum Rhodophyta – Class Florideophyceae – Order Rhodymeniales – Family Rhodymeniaceae
Thallus simple or rarely branched, ovoid to clavate or fusiform, saccate with abundant mucilage, single or clustered from a discoid holdfast. Structure multiaxial, developing a cortex of outer small-celled anticlinal filaments and inner ovoid cells, and a medulla 1–3 cells thick, the inner cells large and bearing secretory cells on their inner sides directly or on derivative cells or their arms.
Reproduction: Gametangial thalli dioecious. Carpogonial branches 4-celled, borne on inner cortical (supporting) cells along with a 2-celled auxiliary cell branch. Carposporophytes directed outwards, with a basal, erect, usually branched fusion-cell and dense, compact, lobes of carposporangia, formed from all cells. Basal nutritive tissue present, with erect filaments of elongate cells not persistent, and short-celled filaments around the ostiole. Cystocarps scattered, only slightly protruding on the thallus surface, more so inwardly, with a thick pericarp, ostiolate. Spermatangia cut off from surface cortical cells via initials.
Tetrasporangia scattered in the slightly thickened cortex, intercalary and transformed from mid cortical cells, with slender pit-connections to outer cortical cells, or decussately divided.
Life history triphasic with isomorphic gametophytes and tetrasporophytes.
Type species: G. brownii Harvey 1859a: pl. 83.
Taxonomic notes: A monospecific genus from southern Australia but also known from New Zealand.
G. Feldmann & Bodard (1965, p. 9) considered that Gloiosaccion could not be separated from Botryocladia, and proposed (see also Silva 1980a, p. 124) that Botryocladia be conserved. However, the two genera differ in habit, in cortical construction, in cystocarp protrusion (see key above) and in how the tetrasporangia are borne, and these features are considered adequate to separate the two genera.
References:
FELDMANN, G. & BODARD, M. (1965). Une nouvelle espèce de Botryocladia des côtes du Sénégal. Bull. Inst. océanogr. Monaco 65 (1342), 1–14.
HARVEY, W.H. (1859a). Phycologia Australica. Vol. 2, Plates 61–120. (Reeve: London.)
SILVA, P.C. (1980a). Remarks on algal nomenclature VI. Taxon 29, 121–145.
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.
|
Email Contact: State Herbarium of South Australia |
|
