Electronic Flora of South Australia Species Fact Sheet
Phylum Rhodophyta – Class Florideophyceae – Order Gelidiales – Family Gelidiaceae
Acrocarpus ramellosus Kützing 1843: 405; 1849: 762; 1868: 12, pl. 34d-g. Sonder 1848: 174.
Echinocaulon ramellosum (Kützing) Feldmann 1931: 8, figs 1–3.
Thallus (Fig. 34A) red-brown, growing as a sparse turf amongst coralline algae, with prostrate stolons producing occasionally branched erect branches about 1 cm high. Erect branches terete, 250–300 µm in diameter below, laterals relatively long, sparse to clustered, 140–200 µm in diameter, branch tips tapering abruptly to the apical cell. Holdfast unknown, reported on shells. Structure of a cortex 3–4 cells thick, with the outer cortical cells in surface view in vague rows, slightly elongate [LB (1–) 1.5–3] and often angular, 3–6 µm broad; medulla (Fig. 34B) of uniform elongate cells, 10–18 µm in diameter, without rhizines; axial cell and periaxial derivatives not apparent in cross section.
Reproduction: Sexual plants unknown.
Tetrasporangial stichidia (Fig. 34C) on the erect branches and laterals near their bases, irregularly radial but tending to be on two sides, short stalked to sessile, 250–600 µm long
Taxonomic notes: The above description is based on the type material, the precise collection locality of which is uncertain.
G. ramellosa was well illustrated by Kützing, and appears to be a distinctive species with its terete branches, elongate and angular cortical cells in surface view, and the short, lateral, stichidia with whorls of 8–15 tetrasporangia. The descriptions of Feldmann (1931), Feldmann & Hamel (1936) and Boudouresque (1967, p. 152, figs 1–7) are doubtfully of the same species, since the plants from Tunisia are recorded as having compressed or flat branches, the branching as pinnate, and the tetrasporangia as tetrahedrally divided. Comments by Maggs & Guiry (1987, p. 429) that G. ramellosa has the tetrasporangia in "chevrons" apply to Mediterranean plants. Records from Japan (Yoshida et al. 1990, p. 290) also need substantiation.
BOUDOURESQUE, C.-F. (1967). Gelidiella ramellosa (Kützing)Feldmann et Hamel et Antithamnion heterocladum Funk, Rhodophycées rares ou nouvelles pour la flore française. Annls Soc. Sci. nat. Arch. Toulon- Var 19, 152–161.
FELDMANN, J. & HAMEL, G. (1934). Observations sur quelques Gélidiacées. Rev. Gen. Bot. 46, 528–549.
FELDMANN, J. & HAMEL, G. (1936). Floridées de France VII. Gélidiales. Rev. Alg. 9, 85–140, Plates 2–6.
FELDMANN, J. (1931). Note sur quelques algues marines de Tunisie. St. Océanogr. Salammbô Notes No. 24, 1–20.
KÜTZING, F.T. (1843). Phycologia generalis. (Leipzig.)
KÜTZING, F.T. (1849). Species Algarum. (Leipzig.)
KÜTZING, F.T. (1868). Tabulae Phycologicae. Vol. 18. (Nordhausen.)
MAGGS, C.A. & GUIRY, M.D. (1987). Gelidiella calcicola sp. nov. (Rhodophyta) from the British Isles and northern France. Br. phycol. J. 22, 417–434.
SONDER, O.W. (1848). Algae. In Lehmann, C., Plantae Preissianae. Vol. 2, pp. 161–195. (Hamburg.)
YOSHIDA, T., NAKAJIMA, Y. & NAKATA, Y. (1990). Check-list of marine algae of Japan (revised in 1990). Jap. J. Phycol. (SO rui) 38, 269–320.
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.
Illustration in Womersley Part IIIA, 1994: FIG. 34 A–C.
Figure 34 enlarge
Fig. 34. A–C. Gelidiella ramellosa (L, 941, 11...11, isotype fragment). A. Branch system with stichidia. 13. Transverse section of thallus. C. Stichidium with apical cell and tetrasporangia, cortical cells shown below. D–J. Gelidiella minima (AD, A60496, holotype). D. Thallus with a stichidium. E. Apex of a male branch showing cortical cell arrangement and spermatangia (below, central). F. Transverse section of an erect branch with five rhizines. G. Transverse section of a male branch, showing axial cell, secondary transverse row and cortical cells; spermatangia on upper surface. H. Section of a cystocarp, showing carposporangia, elongate arachnoid cells and ostiole. I. Surface view of a stichidium with tetrasporangia. J. Cross section of a stichidium. K–N. Gelidiella antipai (AD, A59079). K. Thallus with stolon and erect branches. L. Cross section of branch showing axial cell, secondary row, and cortical cells. M. A stichidium (segments omitted at dashes) showing tetrasporangial whorls and cortical cells (below). N. Cross section of stichidium with a whorl of four tetrasporangia. [D, E, G–J also used in Guiry & Womersley 1992]
State Herbarium of South Australia