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Genus MARTENSIA Hering 1841: 92, nom.cons.

Phylum Rhodophyta – Family Delesseriaceae

Thallus foliose, with broad fronds with lower solid membranous blades and upper perforate nets or meshes terminated by a continuous terminal membrane, smooth or dentate. Holdfast usually discoid, with a terete stipe; epilithic. Structure. Growth marginal from the terminal membrane, with submarginal intercalary cells dividing numerous times and the filaments separating and forming largely monostromatic segments several cells broad, lying at right-angles to the fronds; secondary lateral segments connect the primary segments forming an interconnected net or mesh; in some species the marginal membrane may give rise to secondary nets.

Reproduction: Gametophytes dioecious. Procarps scattered on the segments of the nets, with a 4-celled carpogonial branch and probably sterile groups. Carposporophytes usually with a basal fusion cell and large lower gonimoblast cells, decreasing in size to the ovoid terminal carposporangia. Cystocarps on the net segments, ovoid, ostiolate, with a thick pericarp of anticlinal cell rows. Spermatangial sori on the net segments, with small cortical cells each cutting off several elongate spermatangia.

Tetrasporangial sori scattered on the net segments or the lower membrane, rounded, with tetrasporangia transformed directly from or cut off from primary cells and covered by smaller cortical cells, subspherical, tetrahedrally divided.

Type species: M. elegans Hering 1841: 92.

Taxonomic notes: Martensia includes 5 or 6 species, with probably a single species on southern Australian coasts but 2 or 3 other species on warmer water eastern and western coasts (see Millar 1990, p. 416). Records of M denticulata and M. elegans from southern coasts (e.g. Huisman & Walker 1990, p. 430; Lucas 1909: 135; Lucas & Perrin 1947, pp 216–218; May 1965, p. 466) probably apply to M australis.

Neomartensia [N. flabelliformis (Harvey) Yoshida & Mikami from Japan] has recently been separated by Yoshida & Mikami (1996) from Martensia on account of having carposporangia in chains and membranes with transverse sections showing irregular cells. This species occurs in the central to southern-eastern Pacific, including Lord Howe I.


HERING, K. (1841). XII. Diagnoses Algarum novarum a cI. Dr. Ferdinand Krauss in Africa Australi lectarum. Ann. Mag. Nat. Hist. 8, 90–92.

HUISMAN, J.M. & WALKER, D.I. (1990). A catalogue of the marine plants of Rottnest Island, Western Australia, with notes on their distribution and biogeography. Kingia 1, 349–459.

LUCAS, A.H.S. & PERRIN, F. (1947). The Seaweeds of South Australia. Part 2. The Red Seaweeds. (Govt Printer: Adelaide.)

LUCAS, A.H.S. (1909). Revised list of the Fucoideae and Florideae of Australia. Proc. Linn. Soc. N.S.W. 34, 9–60.

MAY, V. (1965). A census and key to the species of Rhodophyceae (red algae) recorded from Australia. Contr. N.S. W. Natl Herb. 3, 349–429.

MILLAR, A.J.K. (1990). Marine Red Algae of the Coffs Harbour Region, northern New South Wales. Aust. Syst. Bot. 3, 293–593.

YOSHIDA, T. & MIKAMI, H. (1996). Observations on Japanese species of the genus Martensia (Delesseriaceae, Rhodophyta), with the description of Neomartensia gen. nov. Phycol. Research 44, 101–106.

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

Author: H. B. S. Womersley

Publication: Womersley, H.B.S. (24 February, 2003)
The Marine Benthic Flora of Southern Australia
Rhodophyta. Part IIID. Ceramiales – Delesseriaceae, Sarcomeniaceae, Rhodomelaceae
Reproduced with permission from The Marine Benthic Flora of Southern Australia Part IIID 2003, by H.B.S. Womersley. Australian Biological Resources Study, Canberra. Copyright Commonwealth of Australia.

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