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Electronic Flora of South Australia Species Fact Sheet

Nemalion helminthoides* (Velley) Batters 1902: 59.

Phylum Rhodophyta – Class Florideophyceae – Order Nemaliales – Family Liagoraceae

Selected citations: Chapman 1969: 54, pl. 5. Chen et al. 1978: 191, figs 1–21. Dixon & Irvine 1977b: 142, fig. 53. Lucas & Perrin 194'7: 131, fig. 7. Millar & Kraft 1993: 8. Womersley 1950: 163, fig. 2; 1965: 455, figs 1–9, p1. 1.


N. multifidum (Weber & Mohr) J. Agardh 1841: 453. De Toni 1897: 78. Levring 1953: 490.

Thallus (Fig. 18A, B) brown-purple, 5–20 (–30) cm high, simple, basally furcate once or more, or subdichotomously to irregularly branched several times, sometimes proliferous especially near the base, 1–2 (–3) mm in diameter below and tapering slightly above to 0.5–1 mm in diameter. Holdfast discoid, 1–5 mm across; epilithic. Structure multiaxial, with a medulla of densely packed slender filaments and a cortex 300–600 µm thick, consisting of an inner cortex of slender, elongate cells, almost colourless, and outer cortex (Fig. 19A) of subdichotomous filaments of elongate-ovoid assimilatory cells, 6–9 (–14) µm in diameter and L/D 2–4. Rhodoplasts (Fig. 19B) axile, stellate edged, with a very large central pyrenoid. Hairs present on terminal cortical cells on young branch apices.

Reproduction: Sexual thalli usually dioecious, sometimes monoecious. Carpogonial branches (Fig. 19A) straight, formed in outer cortex as a (3–) 4–8-celled branch with a terminal elongate-conical carpogonium and the 2 or 3 subterminal cells showing denser contents; filaments of outer cortex overtopping carpogonial branches. Zygote dividing transversely (Fig. 19C), the upper cell then dividing obliquely or almost longitudinally to form a plate of cells (Fig. 19C, D) which form a dense globular head of branched, radiating gonimoblast filaments (Fig. 19E) with terminal carposporangia 8–12 µm long by 5–8 µm in diameter. Carposporophyte very compact, lying within outer cortex, 60–100 µm across in surface view. Pit-connections of carpogonial branch cells often broadening following fertilization, sometimes forming a slight fusion cell (Fig. 19E). Sterile filaments, similar to the outer cortical filaments, usually develop from the lower cells of the carpogonial branch following fertilization (Fig. 19C, D), forming a slight involucre around the carposporophyte (Fig. 19E). Spermatangial clusters varying (probably with age and activity of growth) from digitate clusters (when young, often somewhat unilateral in spermatangial arrangement), to cells bearing 2 or 3 chains of spermatangial initials, each chain 4–7 cells long (Fig. 19F) with each cell bearing radially several spermatangia 2–3 µm in diameter.

Tetrasporophyte known mainly in culture (rarely in the field - see Fries 1969), filamentous, branched, producing monosporangia and cruciately divided tetrasporangia (Chen et al. 1978).

Type from Portland, England; lectotype in LIV (see Dixon & Irvine 1977b, p. 142).

Selected specimens: Point Sinclair, S. Aust., mid eulittoral (Woelkerling, 3.xi.1968; AD, A34122). Pearson I., S. Aust., mid eulittoral (Specht, 17.ii.1960; AD, A24521). Port Hughes, S. Aust., mid eulittoral (Womersley, 13.x.1988; AD, A59219 -"Marine Algae of southern Australia" No. 76c). Middle R., Kangaroo I., S. Aust., mid eulittoral (Womersley, 19.i.1947; AD, A29293 and 15.i.1965; AD, A28987 -"Marine Algae of southern Australia" No. 76a). Ballast Head, Kangaroo I., S. Aust., mid eulittoral (Womersley, 3.i.1948; AD, A9462 and 28.xii.1948; AD, A10455). Port Elliot, S. Aust., mid eulittoral (Womersley, 25.x.1958; AD, A21887). Point Lonsdale, Vic., mid eulittoral (Womersley, 21.i.1967; AD, A31481 -"Marine Algae of southern Australia" No. 76b). Catamaran (S of Southport), Tas., lower eulittoral (Wollaston & Mitchell, 27.ii.1964; AD, A27687). Long Reef, Collaroy, N.S.W. (Philson & Earle, 26.xii.1934; AD, A49962 -Tilden's "South Pacific Plants" Ser. 2, No. 301). Pearl Beach (N of Broken Bay), N.S.W. (V. Benes, Feb. 1950; AD, A15966).

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

Distribution: World-wide on temperate coasts during summer.

Point Sinclair, S. Aust., around Victoria and Tasmania to Pearl Beach, N.S.W., usually on rocky headlands, mid eulittoral, during summer (late August to early March).

Taxonomic notes: N. helminthoides and N. multifidum have been kept as distinct species by some authors (e.g. Söderström 1970), but united by most authors (see Womersley 1965, p. 457; Dixon & Irvine 1977b, p. 144; Garbary et al. 1983, p. 87). Cunningham & Guiry (1989, p. 705) have shown that in Ireland the macroscopic gametophytes occurred under long-day conditions and the microscopic tetrasporophyte under short days in winter.


AGARDH, J.G. (1841). In historiam algarum symbolae. Linnaea 15, 1–50, 443–457.

CHAPMAN, V.J. (1969). The marine algae of New Zealand. Part III: Rhodophyceae. Issue 1: Bangiophycidae and Florideophycidae (Némalionales, Bonnemaisoniales, Gélidiales). (Cramer: Germany.)

CHEN, L.C.M., EDELSTEIN, T., BIRD, C. & YABU, H. (1978). A culture and cytological study of the life history of Nemalion helminthoides (Rhodophyta, Nemaliales). Proc. N. S. Inst. Sci. 28, 191–199.

CUNNINGHAM, E.M. & GUIRY, M.D. (1989). A circadian rhythm in the long-day photoperiodic induction of erect axis development in the marine red alga Nemalion helminthoides. J. Phycol. 25, 705–712.

DE TONI, G.B. (1897). Sylloge Algarum omnium hucusque Cognitarum. Vol. 4. Florideae. Sect. 1, pp. 1–388. (Padua.)

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.]

FRIES, L. (1969). The sporophyte of Nemalion multifidum (Weber et Mohr) J. Ag. found on the Swedish west coast. Sv. Bot. Tidskr. 63, 139–141, Plates 1–3.

GARBARY, D.J., HANSEN, G.I. & SCAGEL, R.F. (1983). The marine algae of British Columbia and northern Washington: Division Rhodophyta (red algae), Class Florideophyceae, Orders Acrochaetiales and Nemaliales. Syesis 15 (suppl.), 1–102.

LEVRING, T. (1953). The marine algae of Australia. I. Rhodophyta: Goniotrichales, Bangiales and Némalionales. Arkiv för Bot. Ser. 2, 2, 457–530.

MILLAR, A.J.K. & KRAFT, G.T. (1993). Catalogue of Marine and Freshwater Red Algae (Rhodophyta) of New South Wales, including Lord Howe Island, South-western Pacific. Aust. Syst. Bot. 6, 1–90.

SÖDERSTRÖM, J. (1970). Remarks on the European species of Nemalion. Bot. Mar. 13, 81–86.

WOMERSLEY, H.B.S. (1950). The marine algae of Kangaroo Island. III. List of Species 1. Trans. R. Soc. S. Aust. 73, 137–197.

WOMERSLEY, H.B.S. (1965). The Helminthocladiaceae (Rhodophyta) of southern Australia. Aust. J. Bot. 13, 451–487, Plates 1–7.

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

Author: 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.

Illustrations in Womersley Part IIIA, 1994: FIGS 18A, B, 19 A–F.

Figure 18 image

Figure 18   enlarge

Fig. 18. A, B. Nemalion helminthoides (A, AD, A59219; B, AD, A10455). Habit. C. Helminthora lindaueri (AD, A28195). Habit. D. Helminthora australis (AD, A8726). Habit. [B–D as in Womersley 1965.]

Figure 19 image

Figure 19   enlarge

Fig. 19. A–F* Nemalion helminthoides (A, AD, A9462; B, AD, A59219; C, D, E, AD, A29293; F, AD, A21887). A. Cortical filaments with a carpogonial branch. B. Cortical cells each with a large central pyrenoid within a slightly stellate rhodoplast. C, D. Early stages of gonimoblast formation. E. Sectional view of almost mature carposporophyte, surrounded by sterile filaments. F. Spermatangial branches. G–K. Helminthora lindaueri (G, I, J, AD, A24035; H, K, AD, A28070). G. Cortical filaments with a carpogonial branch. H. Cortical cells each with a central pyrenoid and irregularly stellate rhodoplast. I. Young gonimoblast and fusion cell, with sterile bridging filaments. J. Almost mature carposporophyte with sterile involucral filaments and descending rhizoids. K. Spermatangial branch. L. Camontagnea oxyclada (AD, A61772). Apical and subapical cells of an indeterminate branch, with rhodoplasts (with pyrenoids) and a central nucleus. M. Camontagnea hirsuta (AD, A27746). Apical and subapical cells of an indeterminate branch, with rhodoplasts (with pyrenoids) and a central nucleus. [A, C–G, I–K after Womersley 1965.]
* In the following drawings of Liagoraceae, sterile filaments associated with carposporophyte development are shown with broken lines.

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