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Rhodymenia stenoglossa J. Agardh 1885: 50.

Phylum Rhodophyta – Class Florideophyceae – Order Rhodymeniales – Family Rhodymeniaceae

Selected citations: Dawson 1941: 138. De Toni 1900b: 520. Kylin 1931: 21, pl. 7 fig. 18. May 1965: 407. Tisdall 1898: 506. Wilson 1892: 178.

Thallus (Fig. 24A) medium to dark red-brown, 10–25 cm high, with numerous erect, cartilaginous fronds from a clumped base, fronds flat, simple to distantly furcately branched at intervals of 2–5 cm, or with short, often spathulate upper laterals; branches more or less linear, 1–3 mm broad and 90–280 µm thick, apices rounded; stipes short, compressed. Holdfast crustose, 5–15 mm across, bearing numerous fronds; epilithic. Structure multiaxial, developing a cortex 3–4 cells broad (Fig. 24C, E), outer cells ovoid and 3–4 µm in diameter, grading over 2–4 cells to the medulla 2–5 cells broad in young parts, 8–15 cells thick in older parts (Fig. 24B), cells ovoid and 20–45 µm in diameter, thick walled when older. Rhodoplasts discoid to elongate, in chains in inner cells.

Reproduction: Gametangial thalli probably dioecious. Carpogonial branches not observed. Carposporophytes (Fig. 24D) 350–450 µm across with an erect basal fusion cell bearing dense lobes of ovoid carposporangia 10–15 µm in diameter. Basal nutritive tissue slight, erect filaments mostly disintegrating. Cystocarps on the blade surface, usually angled to the surface, ovoid, basally constricted, 600–900 µm in diameter, pericarp 90–200 (–300) µm and 10–15 cells thick, inner cells periclinally elongate, outer cells in chains; ostiolate. Spermatangia not observed.

Tetrasporangia (Fig. 24E, F) in sori near apices of upper branchlets, on one or both sides, probably intercalary, with outer and mid cortical cells becoming elongate and cutting off small outer cells; tetrasporangia ovoid, 25–50 µm long and (12–) 15–25 µm in diameter, decussately divided.

Type from "Nova Holl. aust." (J.B. Wilson); from Back Beach, Sorrento, Vic. (Kylin 1931, p. 21); lectotype (Kylin) in Herb. Agardh, LD.

Selected specimens: Cape Lannes, S. Aust., just above low water in surf (Kraft 4411, 10.ii.1973; MELU, 38408). Warrnambool, Vic., low eulittoral on roof of rock overhang (G. & R. Kraft, 3.i.1995; MELU, K10414; AD, A64515). Marengo Reef, Apollo Bay, Vic., in shallow water, shaded, rear reef (Kraft 6913 & Ricker, 21.iv.1979; MELU, 38410). Portsea, Vic., 2–4 m deep on jetty (O'Brien, 1.x.1975; MELU, 38415). Near Cat Bay, Phillip I., Vic., lower eulittoral (M. Warren, 14.xi.1970; MELU, 38414; AD, A64527). Seal Rocks, Phillip I., Vic. (Seebeck, 30.xi.1965; MELU, 2430). Hunter I., NW Tas., sublittoral (King, 15.xii.1969; MELU, 20349).

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

Distribution: Cape Lannes, S. Aust., to Phillip I., Vic., and Hunter I., Tas.

Taxonomic notes: R. stenoglossa is distinguished largely by its habit of clumps of erect, narrow, linear and sparsely branched fronds from a crustose holdfast. It is apparently not a common species and most collections are by Dr G.T. Kraft and his students.


AGARDH, J.G. (1885). Till algernes systematik. VII. Florideae. Acta Univ. lund. 21, 1–120, Plate 1.

DAWSON, E.Y. (1941). A review of the genus Rhodymenia with descriptions of new species. Allan Hancock Pacif. Exped. 3(7), 115–181.

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.

TISDALL, H.T. (1898). The algae of Victoria. Rep. 7th Meet. Aust. Ass. Adv. Sci., Sydney, 1898, pp. 493–516.

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.

Illustration in Womersley Part IIIA, 1996: FIG. 24.

Figure 24 image

Figure 24   enlarge

Fig. 24. Rhodymenia stenoglossa (A, AD, A64515; B, E, F, MELU, 38414; C, D, MELU, 38415). A. Habit. B. Transverse section of older branch. C. Section of cystocarp with partly displaced carposporophyte. D. Section of cystocarp with carposporophyte, erect fusion cell and slight basal nutritive tissue. E. Transverse section of branch with tetrasporangial sorus. F. Transverse section of branch with tetrasporangia.

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