Electronic Flora of South Australia Species Fact Sheet

Semnocarpa corynephora (J. Agardh) Huisman, Foard & Kraft 1993: 146, figs 1–17.

Phylum Rhodophyta – Class Florideophyceae – Order Rhodymeniales – Family Lomentariaceae

Synonyms

Chylocladia corynephora J. Agardh 1890: 23; 1896: 87. De Toni 1900b: 577. Wilson 1892: 180.

Lomentaria corynephora (J. Agardh) Kylin 1931: 27, pl. 15 fig. 34. May 1965: 361.

Thallus (Fig. 60A) medium red to grey-red, mucilaginous, (3–) 6–10 (–20) cm high, pyramidal in outline, with one or a few percurrent axes bearing irregularly radially laterals for 2–3 orders. Main axes terete to slightly compressed, 1–3 mm broad, laterals terete, 1–2 mm broad, ultimate branchlets clavate, 0.5–1 mm broad, apices rounded, bases constricted. Holdfast discoid, 1–3 mm across, with several fronds; epiphytic on various algae or epilithic. Structure multiaxial, with a cluster of apical cells producing a cortex of a single layer of large inner cells 30–80 µm across and an outer cortex 1–2 cells thick, outer cells ovoid and 5–10 µm in diameter, with a medulla of a network of branched filaments (5–10 µm broad) adjacent to the cortex, with some cells bearing ovoid secretory cells 10–20 µm in diameter. Constrictions (Fig. 60B) pseudoparenchymatous, 220–320 µm long, with filaments on each side. Rhodoplasts discoid, in chains in inner cells.

Reproduction: Gametangial thalli dioecious. Carpogonial branches 3-celled, borne on inner cortical cells near branch apices, with 2-celled auxiliary cell branches. Carposporophyte (Fig. 60D) with basal partly fused cells and all upper cells forming lobes of ovoid carposporangia 40–60 µm in diameter, surrounded by an involucre (Fig. 60D) of lax erect filaments from the auxiliary cell initial; cystocarps (Fig. 60C) immersed in the branchlet, 500–650 µm in diameter, with a small ostiole formed by cortical proliferation. Spermatangia unknown.

Tetrasporangia in scattered, depressed, sori (Fig. 61A, B) 120–180 µm across, and 180–200 µm deep, cut off laterally from cells lining the depression, (50–) 75–110 µm in diameter, tetrahedrally divided.

Type from Western Port, Vic. (Wilson, 24.i.1885); holotype in Herb. Agardh, LD, 25827.

Selected specimens: Yanchep, W. Aust., drift on Amphibolis antarctica (Kraft & Herrington, 29.ix.1990; MELU, A40012). Pearson Is, S. Aust., 30–32 m deep on Codium galeatum (Shepherd, 7.i.1969; AD, A33693). Point Avoid, S. Aust., drift (Womersley, 2.xii.1975; AD, A46891). Investigator Strait, S. Aust., 33 m deep (Watson, 4.i.1971; AD, A41068). Vivonne Bay, Kangaroo I., S. Aust., drift (Womersley, 14.i.1948; AD, A6850). Stinky Bay, Nora Creina, S. Aust., drift (Womersley, 7.xi.1965; AD, A29644). Warrnambool, Vic., drift (Kraft & Herrington, 28.x.1988; MELU, A40014). Port Phillip Heads, Vic. (Wilson, 14.i.1885; MEL, 612087).

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

Distribution: Yanchep, W. Aust., to Western Port, Vic.

References:

AGARDH, J.G. (1890). Till algernes systematik. Acta Univ. lund. 26(3), 1–125, Plates 1–3.

AGARDH, J.G. (1896). Analecta Algologica. Cont. III. Acta Univ. lund. 32, 1–140, Plate 1.

DE TONI, G.B. (1900b). Sylloge Algarum omnium hucusque Cognitarum. Vol. 4. Florideae. Sect. 2, pp. 387–776. (Padua.)

KYLIN, H. (1931). Die Florideenordnung Rhodyméniales. Lunds Univ. Årsskr. N.F. Avd. 2, 27 (11), 1–48, Plates 1–20.

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

WILSON, J.B. (1892). Catalogue of algae collected at or near Port Phillip Heads and Western Port. Proc. R. Soc. Vict. 4, 157–190.

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.

Illustrations in Womersley Part IIIA, 1996: FIGS 60, 61A, B.

Figure 60   enlarge

Fig. 60. Semnocarpa corynephora (AD, A33693). A. Habit. B. Longitudinal section through a constriction. C. Branch with three cystocarps. D. Longitudinal section of thallus with a cystocarp, showing basal fusion cell, prominent erect filaments, and displaced carposporangia.

Figure 61   enlarge

Fig. 61. A, B. Semnocarpa corynephora (AD, A33693). A. Surface view of tetrasporangial sori. B. Section of branch with tetrasporangial sori, the lower one without tetrasporangia. C–E. Semnocarpa minuta (C, AD, A42379; D, AD, A42927; E, AD, A61202). C. Longitudinal section of thallus on Rhodymenia. D. Section of a cystocarp, with basal fusion cell, erect filaments and carposporangia. E. Thallus with tetrasporangia.

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