Electronic Flora of South Australia Species Fact Sheet

Gymnogongrus griffithsiae (Turner) Martius 1828: 27.

Phylum Rhodophyta – Class Florideophyceae – Order Gigartinales – Family Phyllophoraceae

Selected citations: Dixon & Irvine 1977b: 219, fig. 79. Gregory 1934: 532, figs 1–11. Harvey 1847: pl. 108. Schotter 1968: 62, figs 35,36.

Synonym

Fucus griffithsii Turner 1808: 80, pl. 37.

Thallus (Fig. 84G) dark red-brown, densely tufted, 1.5–4 cm high, cartilaginous, subdichotomously and more or less complanately branched at intervals of 1–10 mm, branches terete to slightly compressed above, 200–400 (–900) µm broad throughout with slightly slenderer rounded apices; holdfast thin, crustose, 1–5 mm across, with numerous erect fronds; epilithic. Structure multiaxial, with ovoid cells throughout, cortical cells in short anticlinal rows (3–) 4–5 µm in diameter and L/D 1–2; medullary cells 10–20 µm in diameter and L/D 4–8 (–10), often tiered in longitudinal section and with numerous secondary pit-connections. Rhodoplasts laminate and few per cortical cell, becoming ribbon shaped and branched in medullary cells.

Reproduction: Only female thalli known, bearing pustules containing nemathecia of tetrasporangia. Carpogonial branches arising in the inner cortex, with a large, ovoid, supporting cell bearing a 3-celled carpogonial branch. Gonimoblast filaments 4–5 µm in diameter, cells L/D 1–2, arising from a fusion cell and ramifying between the cortical cells, then spreading to form a broad pustule ("tetrasporoblast") (Fig. 84H) on the branch surface situated part way from the apices and often near a dichotomy. Pustules partly to completely surrounding the branch, 150–250 µm thick, with a basal layer of branched radiating filaments, with each cell forming an erect to assurgent filament 5–7 (–10) µm in diameter, cells L/D (1–) 2–3, with the rows of upper cells (terminated by 1–2 sterile cells) maturing to ovoid tetrasporangia 10–12 µm in diameter, cruciately divided shortly before release.

Type from Sidmouth, Devon, England; lectotype in BM.

Distribution map based
on current data relating to
specimens held in the
State Herbarium of SA

Distribution: British Isles, Western Europe, Mediterranean, Eastern U.S.A. to Uruguay.

In southern Australia, known from the south coast of Kangaroo I., S. Aust., and Barwon Heads, Vic., in pools near low tide level.

Taxonomic notes: The southern Australian specimens agree well with those from the British Isles and Europe, and occur in similar ecological situations.

References:

DIXON, P.S. & IRVINE, L.M. (1977b). Seaweeds of the British Isles. Vol. 1, Rhodophyta. Part I, Introduction, Nemaliales, Gigartinales. [British Museum (N.H.): London.]

GREGORY, B.D. (1934). On the life-history of Gymnogongrus griffithsiae Mart. and Ahnfeltia plicata Fries. J. Linn. Soc., Bot. 49, 531–551.

HARVEY, W.H. (1847). Phycologia Britannica. Plates 73–144. (Reeve: London.)

MARTIUS, C.F.P. (1828). Flora Brasiliensis. I. (Stuttgart & Tubingen.)

SCHOTTER, G. (1968). Recherches sur les Phyllophoracees. Bull. Inst. Océanogr. Monaco 67, 1–99.

TURNER, D. (1808). Fuci sive Plantarum Fucorum Generi a Botanicis Ascriptarum Icones Descriptiones et Historia. Vol. 1, pp. 1–164, Plates 1–71. (London.)

The Marine Benthic Flora of Southern Australia Part IIIA complete list of references.

Author: J.A. Lewis & H.B.S. Womersley

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.

Illustration in Womersley Part IIIA, 1994: FIG. 84G, H.

Figure 84   enlarge

Fig. 84. A, B. Ahnfeltiopsis fastigiate (A, MELU, A39459; B, AD, A27731). A. Habit. B. Transverse section of cystocarp. C–F. Ahnfeltiopsis humilis (C, E, F, AD, A61516; D, AD, A21294). C. Habit, mature plants. D. Habit of larger, much branched, plant. E. Transverse section of cystocarp. F. Transverse section of thallus with surface pustule. G, H. Gymnogongrus griffithsiae (AD, A20336). G. Habit. H. Longitudinal section of thallus with tetrasporoblast pustules.

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