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Electronic Flora of South Australia Species Fact Sheet

Melobesia membranacea (Esper) Lamouroux 1812: 186.

Phylum Rhodophyta – Class Florideophyceae – Order Corallinales – Family Corallinaceae – Subfamily Melobesioideae

Selected citations: Chamberlain 1985: 673, figs 1–4. Chamberlain & Irvine 1994c: 196, figs 7B, 39A, 75, 93, 94. Harvey 1863, synop.: xxx. Rosanoff 1866: 66, pl. II figs 13–16, pl. III fig. 1. Wilks & Woelkerling 1991: 522, figs 1–22. Woelkerling 1988: 197, figs 214–216.


Corallina membranacea Esper 1806: Corallina Tab. XII.

Epilithon membranaceum (Esper) Heydrich 1897a: 408. Kylin 1928: 7, figs 19–21. Suneson 1937: 59, fig. 36.

Lithothamnion membranaceum (Esper) Foslie 1898b: 7. Lucas 1912: 162; 1931b: 57.

Melobesia corticiformis Kützing 1849: 696. Barton 1893: 202.

Thallus normally pinkish, encrusting, mostly 0.4–15 mm across and 10–75 µm thick, epigenous and completely affixed by cell adhesion. Structure pseudoparenchymatous with dorsiventral organisation throughout; construction dimerous, consisting of a single ventral layer of branched, laterally cohering, filaments each composed of palisade or non-palisade cells 2–13 µm long and 2–30 µm high, and additionally of epithallial cells or multicellular simple or branched, laterally cohering, filaments that arise dorsally and more or less perpendicularly from most cells of ventral layer filaments and are each composed only of an epithallial cell 2–10 µm in diameter and 2–8 µm long or with additional subtending cells 2–15 µm in diameter and 2–15 µm long; distal walls of epithallial cells rounded or flattened but not flared; cell elongation characteristics uncertain; cells of adjacent filaments joined by cell-fusions; secondary pit-connections, haustoria, and trichocytes not observed.

Reproduction: Vegetative reproduction unknown. Gametangia and carposporophytes produced in uniporate conceptacles; tetrasporangia produced in multiporate conceptacles; bisporangia not observed.

Gametangial thalli monoecious or dioecious; carpogonia and spermatangia produced in separate conceptacles. Carpogonia terminating 2- or 3-celled filaments arising from the female conceptacle chamber floor. Mature female-carposporangial conceptacle roofs protruding above or flush with surrounding thallus surface, 5–25 (–40) µm thick, composed of 2–8 layers of short, squat cells, conceptacle chambers 50–250 µm in diameter and 25–80 µm high. Carposporophytes when mature apparently consisting of one (or several?) inconspicuous fusion cells bearing several-celled gonimoblast filaments with terminal carposporangia 18–60 µm in diameter. Spermatangial filaments unbranched, arising from the floor, walls and roof of male conceptacle chambers, mature male conceptacle roofs protruding above or flush with surrounding thallus surface, 7–20 µm thick, composed of 2–7 layers of more or less squat cells, conceptacle chambers 57–130 µm in diameter and 25–40 µm high.

Tetrasporangial conceptacle roofs protruding above or flush with surrounding surface, commonly but not always differentiated into a peripheral rim and a central sunken pore-plate, pore-plate composed of cells that are similar in size and shape to other roof cells, roof 2–5 cells thick above the chamber, conceptacle chambers (35–) 50–252 µm in diameter and 15–83 µm high; tetrasporangial initials situated one cell layer below the thallus surface, scattered across the conceptacle chamber floor, each mature sporangium 10–53 µm in diameter and 22–65 µm long, containing zonately arranged tetraspores and possessing an apical plug that blocks a roof pore prior to spore release; bisporangia not observed.

Type from an unspecified locality in France; neotype in CN (unnumbered); designated by Chamberlain (1985, p. 677); depicted in Chamberlain (1985, p. 675 fig. 2) and Wilks & Woelkerling (1991, p. 509, fig. 1).

Selected specimens: Flat Rock (30 km N of Dongara), W. Aust. (Woelkerling, 26.ii.1979; LTB, 14849), Port Denison, W. Aust., outer reef pools (Woelkerling, 8.xi.1968; AD, A60520 = LTB, 16060). Esperance (Twilight Cove), W. Aust. (Woelkerling, 29.i.1978; LTB, 14881). Great Australian Bight (32124'S, 133130'E), S. Aust., 42 m deep (Symond, 5.v.1973; AD, A60353 = LTB, 16075). Elliston, S. Aust., 13 m deep (Woelkerling, 16.v.1968; AD, A60581 = LTB, 16121). Port Elliot, S. Aust., drift (Womersley, 17.x.1948; AD, A60578 = LTB, 16118). Cape du Couedic, Kangaroo I., S. Aust., shaded littoral pools (Womersley, 16.i.1965; AD, A60529 = LTB, 16069). Nora Creina, S. Aust., 0–3 m deep (Campbell & Penrose, 6.xi.1987; LTB, 15801). Beachport (Three Mile Rocks), S. Aust., on Caulerpa cactoides (Wilks, 17.ii.1990; LTB, 16030 and 20.ii.1990; LTB, 16034) and (Woelkerling, 26.ii.1988; LTB, 15981, 15983). Port MacDonnell, S. Aust. (Woelkerling, 12.ii.1989; LTB, 16020). Bridgewater Bay, Vic., drift (Beauglehole, 17.vii.1949; AD, A60548 = LTB, 16088). Rye (Number 16 reef, Ocean Beach), Vic., rock pool (Platt & Woelkerling, 21.xii.1982; LTB, 12612). Kitty Miller Bay, Phillip I., Vic., 0–2 m deep (Wilks & Penrose, 11.xii.1989; LTB, 15913). Gabo I., Vic., 13 m deep (Shepherd, 14.ii.1973; AD, A60538 = LTB, 16078). East Cove, Deal I., Tas., 1 m deep (Shepherd & Lewis, 5.v.1974; AD, A60561 = LTB, 16101). Fluted Cape, Bruny I., Tas., 16 m deep (Shepherd, 12.ii.1972; AD, A60543 = LTB, 16083). Clydes I., Eaglehawk Neck, Tas., 0–6 m deep (Platt & Woelkerling, 26.ii.1983; LTB, 13282).

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

Distribution: Widespread, but many records require confirmation (Wilks & Woelkerling 1991, p. 524; Chamberlain & Irvine 1994c, p. 199). In Australia, Flat Rock (30 km N of Dongara), W. Aust., to Gabo I., Vic., and around Tasmania.

Taxonomic notes: Melobesia membranacea occurs epiphytically on a variety of green, brown and red algae in southern Australia and has been found intertidally on rocky reefs and in tide pools and subtidally to depths of 42 m. Dense populations involving vast numbers of thalli commonly occur and usually contain both gametangial and tetrasporangial individuals. Carposporophytes with conspicuous central fusion cells (Kylin 1928, p. 38; Suneson 1937, p. 60) were not found in southern Australian material, but fusion cell morphology in mature carposporophytes requires clarification (see Wilks & Woelkerling 1991, p. 525). Chamberlain & Irvine (1994c, pp. 197,198, fig. 94D) suggest that gonimoblast filaments are borne peripherally from a central agglomeration of fusion cells, but this is not evident in their illustration. Chamberlain & Irvine (1994c, p. 198) also report that tetrasporangia very occasionally have cruciately arranged spores and that bisporangia occur; these have not been observed in southern Australian specimens.

Additional references involving these binomials, previous southern Australian records and known heterotypic synonyms are given by Wilks & Woelkerling (1991).


BARTON, E.S. (1893). A provisional list of the marine algae of the Cape of Good Hope. J. Bot., Lond. 31, 53–56, 81–84, 110–114, 138–144, 171–177, 202–210. Note: also issued as a single, independently paginated offprint (pp. 1–32)

CHAMBERLAIN, Y.M. & IRVINE, L.M. (1994c). Melobesioideaae Bizzozero. In Irvine, L. M. & Chamberlain, Y. M. (Eds), Seaweeds of the British Isles. Volume 1 Rhodophyta Part 2B Corallinales, Hildenbrandiales pp. 159–234. (HMSO: London.)

CHAMBERLAIN, Y.M. (1985). The typification of Melobesia membranacea (Esper) Lamouroux (Rhodophyta, Corallinaceae). Taxon 34, 673–677.

ESPER, E.G.C. (1806). Fortsetzungen der Pflanzenthiere. Vol. 2, Part 10, pp. 25–48. (Raspe: Nurnberg.)

FOSLIE, M. (1898b). List of species of the lithothamnia. K. norske Vidensk. Selsk. Skr. 1898(3), 1–11.

HARVEY, W.H. (1863). Phycologia Australica. Vol. 5, Plates 241–300, synop., pp. i-lxxiii. (Reeve: London.)

HEYDRICH, F. (1897a). Corallinaceae, inbesondere Melobesieae. Ber. dt. bot. Ges. 15, 34–71, Plate 3.

KÜTZING, F.T. (1849). Species Algarum. (Leipzig.)

KYLIN, H. (1928). Entwicklungsgeschichtliche Florideen Studien. Lunds Univ. Årsskr. N.F. Avd. 2, 24 (4), 1–127.

LAMOUROUX, J.V.F. (1812). Sur la classification des Polypiers coralligenès non entièrement pierreux. Nouv. Bull. Sci. Soc. Philom. Paris 3, 181–188.

LUCAS, A.H.S. (1912). Supplementary list of the marine algae of Australia. Proc. Linn. Soc. N.S.W. 37, 157–171.

LUCAS, A.H.S. (1931b). The marine algae hitherto recorded for north-east Australia. Rep. Gt. Barrier Reef. Comm. 3(6), 47–57.

ROSANOFF, S. (1866). Recherches anatomiques sur les Mélobésiées. Mem. Soc. Imper. Sci. Nat. Cherbourg 12, 5–112, Plates 1–7.

SUNESON, S. (1937). Studien über die entwicklungsgeschichte der Corallinaceen. Lunds Univ. Årsskr. N.F. Avd. 2, 33, 1–102, Plates 1–4.

WILKS, K.M. & WOELKERLING, W.J. (1991). Southern Australian species of Melobesia (Corallinaceae, Rhodophyta). Phycologia 30, 507–533.

WOELKERLING, Wm.J. (1988). The Coralline Red Algae. [British Museum (N.H.): London.]

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

Author: W.J. Woelkerling

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.

Illustrations in Womersley Part IIIA, 1996: FIGS 69, 70.

Figure 69 image

Figure 69   enlarge

Fig. 69. Melobesia membranacea (A, LTB, 16101; B, E, LTB, 15801; C, LTB, 16034; D, LTB, 16121; F, LTB, 15913). A. Population of encrusting thalli growing on Laurencia. B. Encrusting thalli with tetrasporangial conceptacles growing on Caulerpa papillose. C. Section of vegetative thallus showing dimerous construction. Note ventral layer of filaments (arrows) from which new filaments arise dorsally. D. Surface view of multiporate tetrasporangial conceptacle. E. Section of mature tetrasporangial conceptacle. F. Portion of tetrasporangial conceptacle roof with a pore canal and bordering filaments.

Figure 70 image

Figure 70   enlarge

Fig. 70. Melobesia membranacea (A, LTB, 16030; B, LTB, 16020; C, LTB, 15981; D, LTB, 15983). A. Section of very young tetrasporangial conceptacle with initials one cell layer below the thallus surface (compare with Fig. 72A of M. rosanoffii). B. Section of female-carposporangial conceptacle with mature carpogonial filaments. C. Section of female-carposporangial conceptacle with mature carposporophyte. D. Section of male conceptacle with mature, unbranched spermatangial filaments arising from chamber floor and roof.

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