Electronic Flora of South Australia
Electronic Flora of South Australia
Census of SA Plants, Algae & Fungi
Identification tools

Electronic Flora of South Australia Genus Fact Sheet

Genus CURDIEA Harvey 1855b: 333

Phylum Rhodophyta – Class Florideophyceae – Order Gracilariales – Family Gracilariaceae

Thallus erect or decumbent, 5–50 cm high or long, coriaceous, variously and irregularly complanately branched with branches strongly compressed and of varying width; holdfast discoid. Structure multiaxial, pseudoparenchymatous throughout, branch apices without distinct caps, outer cortical cells small, in short anticlinal chains, medullary cells large with numerous secondary pit-connections.

Reproduction: Gametangial thalli probably dioecious. Carpogonial branches 2-celled, borne on supporting cells in the mid cortex with adjacent sterile branches. Carposporophyte with a small basal fusion cell producing slight sterile gonimoblast tissue and densely tufted, erect, simple or basally branched, straight chains of numerous subspherical carposporangia maturing apically and largely filling the cystocarp cavity. Cystocarps largely marginal, large and conspicuous, with a thick pericarp of dense filaments of short cells, ostiolate. Spermatangia unknown.

Tetrasporangia in shallow and inconspicuous nemathecia, basally pit-connected to the basal or mid cells of short, 2–5-celled paraphyses, ovoid, cruciately divided.

Life history triphasic with isomorphic gametophytes and tetrasporophytes.

Type species: C. laciniata Harvey 1855b: 333. [= C. angustata (Sonder) Millar]

Taxonomic notes: A genus of about 8 species, from southern and warm temperate Australia, New Zealand, Subantarctic Islands and Chile.

As Millar (1990, p. 340) has noted, Sarcocladia Harvey (1855a, p. 550), with type species S. obesa Harvey, was probably published prior to Curdiea. The former has usually been considered a synonym of Curdiea and there is justification for conserving Curdiea Harvey if dates of publication can be clarified.

A New Zealand species, C. flabellata Chapman, has been investigated in detail by Fredericq & Hommersand (1989c). Southern Australian species include the common and morphologically variable C. angustata, the western, partly erect, C. obesa, and the eastern, decumbent, C. crassa. C. irvineae J. Agardh (1894, p. 135) from Western Australia appears distinct from southern species, having more or less linear branches 3–6 mm broad, usually curved longitudinally with cystocarps on the convex surface, but further comparisons with C. obesa are needed.


AGARDH, J.G. (1894). Analecta Algologica. Cont. I. Acta Univ. lund. 29, 1–144, Plates 1, 2.

FREDERICQ, S. & HOMMERSAND, M.H. (1989c). Reproductive morphology and development of the cystocarp in Curdiea flabellata Chapman (Gracilariales, Rhodophyta). N.Z. J. Bot. 27, 521–530.

HARVEY, W.H. (1855a). Some account of the marine botany of the colony of Western Australia. Trans. R. Ir. Acad. 22, 525–566.

HARVEY, W.H. (1855b). Short characters of some new genera and species of algae discovered on the coast of the Colony of Victoria, Australia. Ann. Mag. Nat. Hist. 15 (ser. 2), 332–336.

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

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

Author: H.B.S. Womersley

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.


1. Thallus erect, much branched irregularly, with similar cortices on both sides; cystocarps marginal

C. angustata

1. Thallus decumbent to partly erect, moderately to slightly branched, with distinct upper and lower cortices; cystocarps on the thallus surface or submarginal


2. Thallus moderately branched and partly erect, 0.5–1.0 mm thick in young parts, 1–1.5 mm thick in older parts; cystocarps usually submarginal

C. obesa

2. Thallus irregularly lobed, decumbent, 1–1.5 mm thick in young parts, 3–4 mm thick in older parts; cystocarps mostly on the surface

C. crassa

Disclaimer Copyright Disclaimer Copyright Email Contact:
State Herbarium of South Australia
Government of South Australia Government of South Australia Government of South Australia Department for Environment and Water