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Electronic Flora of South Australia Species Fact Sheet
Phylum Rhodophyta – Order Ceramiales – Family Dasyaceae
Selected citations: Harvey 1860: pl. 143; 1863; synop.: xxiii. J. Agardh 1863: 1237; 1890a: 97. De Toni 1903: 1193. Kützing 1864: 24, pl. 68a, b. Lucas 1912: 157; 1929a: 23. Lucas & Perrin 1947: 371. Sonder 1881: 36. Wilson 1892: 165. Womersley 1950: 181.
Synonyms
Dasya meredithiae J. Agardh 1890a: 96, pl. 3, fig. 3. De Toni 1903: 1192. Lucas 1912: 157; 1929a: 23.
Rhodonema meredithiae J. Agardh 1890a: pl. 3, fig. 3.
Thallus (Fig. 199A) pale crimson-red to dark red-brown, 15–30 cm high, usually with a single axis. Main axis corticated, 1–2 mm in diameter, regularly to irregularly distichously branched often from very close to the apex; lateral axes usually regularly distichously branched (Fig. 199B), occasionally radially, ultimately bearing spirally arranged, subdichotomous, monosiphonous pseudolaterals. Holdfast discoid, epilithic. Structure. Pericentral cells 5, developed in circular sequence, becoming obscured in transverse sections (Fig. 199C) of older axes by rhizoidal cells which may become much enlarged. Pseudolaterals (Fig. 199B, F) one on each segment, 250–1100 µm long, patent and curved, tapering to an acute apex or rarely forming an attenuate filament, below subdichotomous every 2–3 cells with 3–5 subdichotomies giving 6–20 ultimate branches. Basal cell and lower cells 20–45 µm in diameter, L/D 1–2 (–2.5). Adventitious monosiphonous filaments scattered, arising from cortical cells, unbranched and acute, or subdichotomous resembling smaller pseudolaterals. Intercalary cell divisions absent. Lateral axes arise from the basal cell of the first branch of the pseudolateral, with adventitious lateral axes arising from surface cortical cells, scattered on older parts of the main axes. Rhodoplasts discoid, chained and reticulate even in smaller cells.
Reproduction: Gametophytes dioecious. Procarps spirally arranged on successive segments of lateral polysiphonous and adventitious axes. Carposporophytes with a basal fusion cell and ovoid to subspherical carposporangia, in apical and lateral rows of 2–3. Cystocarps (Fig. 199D) basally embedded in a corticated axis, urceolate, 400–800 µm in diameter, with a distinct neck 0.3–0.5 of the cystocarp diameter in length, either straight or flared with the terminal filaments often extended and free; pericarp 3–4 cells thick, surface often with smaller, simple or subdichotomous, patent, adventitious, monosiphonous filaments. Spermatangial branches (Fig. 199E) sessile or on a 1–2-celled monosiphonous stalk, on the lower branches of the pseudolaterals or adventitious filaments, cylindrical, 170–400 µm long and 45–60 µm in diameter, with or without a short apical filament (1–) 3 (–5) cells long, the apical cell being conical.
Stichidia (Fig. 199F) on a 1–2-celled monosiphonous stalk, on the lower branches of the pseudolaterals or adventitious filaments, cylindrical or occasionally ovoid, (80–) 110–200 (–410) µm long and 70–80 (–90) Rm in diameter, with (2–) 3–12 (–20) fertile segments each with (4–) 5 pericentral cells all of which usually become fertile, the basal segment of 4 pericentral cells with 1–2 (–3) becoming fertile. Each tetrasporangium with 2–3 cover cells, round to broader than high in surface view, which cover less than one quarter of the sporangium and are often moulded around the sporangium.
Type from Phillip I., Vic. (Harvey, Alg. Aust. Exsicc. 222H); lectotype (HBSW) in TCD, isolectotypes MEL, 1006680, 1006659, 1006684
Selected specimens: Geraldton, W. Aust., drift (G. & R. Kraft, 9.x.1990; MELU, K9981). Eyre, W. Aust., drift (Parsons, 22.xi.1968; AD, A34407 - "Marine Algae of southern Australia" No. 113). Head of Great Australian Bight, S. Aust., drift (Parsons, 4.xi.1968: AD, A32945). Troubridge I., S. Aust., 23 m deep (Shepherd, 4.ii.1969; AD, A33833). Elliston, S. Aust., drift (Womersley, 13.i.1951; AD, A13571). Stenhouse Bay, S. Aust., 3–7 m deep (Kraft, 18.ix.1973; AD, A44563). Victor Harbor, S. Aust., drift (Womersley, 14.xi.1965; AD, A29680). Vivonne Bay, Kangaroo I., S. Aust., drift (Woelkerling, 21.ii.1979; AD, A56316; MELU, 22982). 1.3 km off Cape Northumberland, S. Aust., 15m deep (Shepherd, 1.ii.1978; AD, A49151). Port MacDonnell, S. Aust., drift (Womersley, 16.x.1985; AD, A57010). San Remo, Vic., drift (Kraft 5450, 19.x.1975; MELU and AD, A67882). Walkerville, Vic., drift (Kraft 5680, 18.x.1975; MELU). Low Head, Tas. (Perrin, 24.xi.1949; AD, A48207). Orford, Tas. (Meredith, LD, 43938, lectotype of D. meredithiae J. Agardh).
Distribution: Geraldton, W. Aust., to Walkerville, Vic., and around Tasmania.
Taxonomic notes: D. haffiae occurs sublittorally, down to 23 m, often on limestone; it appears to be present and fertile mainly in late spring and summer.
Harvey (1859b, p. 303), described Dasya haffiae from material collected at Georgetown, Tasmania by R. Gunn, from Western Port, Victoria by himself and from Table Cape, Tasmania by Miss Mackenzie. Harvey expressed some doubt, however, about the Table Cape specimens being the same as the others as he felt that they were "much injured and in part denuded of ramelli, and may possibly belong to a different ... species". A re-examination of the Table Cape specimen in TCD has shown that it represents a species of Micropeuce.
The specimen of D. haffiae illustrated by Kützing (1864, p. 24, pl. 68a, b) was collected by Harvey at Western Port, Victoria, and is in the Sonder Herbarium, MEL, 1006680. Harvey left two Western port specimens of Dasya haffiae from his Travelling Set No. 359 (MEL, 1006659, 1006684) with F. Mueller during his visit to Melbourne in 1854. These three MEL specimens are isolectotypes of D. haffiae.
Dasya meredithiae is based on material sent to J. Agardh from Orford, Tasmania by Mrs Meredith and from Swan Island, Bass Strait (LD, 43935) by Miss Baudinet. From the three excellent Orford specimens in Herb. Agardh, LD, 43938 is now selected as the lectotype of D. meredithiae, with LD, 43936, 43937 as syntypes.
The distichous branching of the thallus of D. haffiae is unusual in Dasya. The apex of an axis is sympodial and pseudolaterals develop successively one to each segment in a 2/5 spiral; this is the usual pattern of Dasya. The thallus branching becomes distichous later when the first and second (or second and third) pseudolaterals of any series of five are the only ones which become differentiated into polysiphonous lateral axes. Pseudolaterals 3, 4 and 5 remain as monosiphonous, subdichotomous, patent pseudolaterals. Occasionally pseudolaterals 1, 2 and 3 all become polysiphonous and then the branching of the thallus appears irregular rather than bilateral. The monosiphonous pseudolaterals are very persistent, remaining on the corticated axes of most of the plant.
References:
AGARDH, J.G. (1863). Species Genera et Ordines Algarum. Vol. 2, Part 3, pp. 787–1291. (Gleerup: Lund.)
AGARDH, J.G. (1890a). Till algernes systematik. Acta Univ. lund. 26(3), 1–125, Plates 1–3.
DE TONI, G.B. (1903). Sylloge Algarum omnium hucusque Cognitarum. Vol. 4. Florideae. Sect. 3, pp. 775–1521 + 1523–1525. (Padua.)
HARVEY, W.H. (1859b). Algae. In Hooker, J.D., The Botany of the Antarctic Voyage. III. Flora Tasmaniae. Vol. II, pp. 282–343, Plates 185–196. (Reeve: London.)
HARVEY, W.H. (1860). Phycologia Australica. Vol. 3, Plates 121–180. (Reeve: London.)
HARVEY, W.H. (1863). Phycologia Australica. Vol. 5, Plates 241–300, synop., pp. i-lxxiii. (Reeve: London.)
KÜTZING, F.T. (1864). Tabulae Phycologicae. Vol. 14. (Nordhausen.)
LUCAS, A.H.S. & PERRIN, F. (1947). The Seaweeds of South Australia. Part 2. The Red Seaweeds. (Govt Printer: Adelaide.)
LUCAS, A.H.S. (1912). Supplementary list of the marine algae of Australia. Proc. Linn. Soc. N.S.W. 37, 157–171.
LUCAS, A.H.S. (1929a). The marine algae of Tasmania. Pap. Proc. R. Soc. Tasm. 1928, 6–27.
SONDER, O.W. (1881). In Mueller, F., Fragmenta Phytographiae Australiae. Supplementum ad volumen undecinum: Algae Australianae hactenus cognitae, pp. 1–42, 105–107. (Melbourne.)
WILSON, J.B. (1892). Catalogue of algae collected at or near Port Phillip Heads and Western Port. Proc. R. Soc. Vict. 4, 157–190.
WOMERSLEY, H.B.S. (1950). The marine algae of Kangaroo Island. III. List of Species 1. Trans. R. Soc. S. Aust. 73, 137–197.
The Marine Benthic Flora of Southern Australia Part IIIC complete list of references.
Publication:
Womersley, H.B.S. (24 December, 1998)
The Marine Benthic Flora of Southern Australia
Rhodophyta. Part IIIC. Ceramiales – Ceramiaceae, Dasyaceae
©State Herbarium of South Australia, Government of South Australia
Illustration in Womersley Part IIIA, 1998: FIG. 199.
Figure 199 enlarge
Fig. 199. Dasya haffiae (A, D–F, AD, A34407; B, AD, A32945; C, AD, A33833). A. Habit. B. Branch with alternate, subdistichous laterals and pseudolaterals. C. Transverse section of a branch. D. Cystocarp showing gonimoblast and filaments on pericarp. E. Spermatangial branches. F. Stichidia on pseudolateral branches.
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