Electronic Flora of South Australia Genus Fact Sheet
Phylum Rhodophyta – Class Florideophyceae – Order Nemaliales – Family Galaxauraceae
Thallus (gametophyte) erect, terete, subdichotomously branched, multiaxial, with a medullary core of numerous, slender, branched filaments less than 20% of the thallus diameter in width, producing numerous radiating branched filaments with an assimilatory cortex 2–5 cells broad, smaller celled outwardly and without colourless utricles.
Tetrasporophyte of dense tufts or mats of slender branched filaments, to 1 cm across.
Reproduction: Carpogonial branches 3-celled, the hypogynous cell with 3 sterile branches and with the basal cell producing filaments which form a distinct involucre around the carposporophyte. Gonimoblast filaments arising from the fertilized carpogonium, producing carposporangia in short terminal chains, with a basal fusion cell. Cystocarp urceolate, ostiolate, lying within the outer medulla. Spermatangia borne on the outer cortical cells.
Tetrasporophytes bearing cruciately divided tetrasporangia terminally or laterally, sessile or pedicellate, on the filaments; tetraspores germinating to form a filamentous gametophyte from which the erect gametophytes arise as buds.
Life history triphasic with heteromorphic gametophyte and sporophyte.
Type species: G. scinaioides J. Agardh 1872: 29.
Taxonomic notes: Huisman (1985, p. 407) studied the type species which differs from Scinaia in having no colourless utricles in the outer cortex. The genus has been further surveyed and the life history followed by Huisman (1987).
AGARDH, J.G. (1872). Bidrag till Florideernes Systematik. Acta Univ. hind. 8, 1–60.
HUISMAN, J.M. (1985). The Scinaia assemblage (Galaxauraceae, Rhodophyta): a re- appraisal. Phycologia 24, 403–418.
HUISMAN, J.M. (1987). The taxonomy and life history of Gloiophloea (Galaxauraceae, Rhodophyta). Phycologia 26, 167–174.
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.
KEY TO SPECIES OF GLOIOPHLOEA
1. Thallus subdichotomous, branches
1. Thallus with numerous short laterals
State Herbarium of South Australia