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

Electronic Flora of South Australia Species Fact Sheet

Dasya villosa Harvey 1844: 433; 1847: 61, pl. 20; 1855a: 543; 1859b: 302; 1863, synop.: xxii.

Phylum Rhodophyta – Order Ceramiales – Family Dasyaceae

Selected citations: J. Agardh 1863: 1215; 1890a: 103, in part. De Toni 1903: 1203; 1924: 442. De Toni & Forti 1923: 51. Kützing 1849: 796; 1864: 21, pl. 57. Lucas 1912: 158; 1929a:


23; 1929b: 52. Lucas & Perrin 1947: 312, in part. Mazza 1910: No. 346. Parsons 1975: 568, fig. 39A. Reinbold 1899: 49. Silva et al. 1996: 438. Sonder 1853: 702; 1881: 36. Wilson 1892: 165, in part. Womersley 1950: 182, in part. NON J. Agardh 1890a: 103, in part. Reinbold 1898: 50. Lucas & Perrin 1947: fig. 150. Womersley 1966: 152 (all D. extensa Sonder ex Kützing).

Endogenia gracilaria J. Agardh 1897: 52, pl. 1 fig. 14.

Thallus (Fig. 194A) red-brown to very dark brown, occasionally light red, mucilaginous, 10–40 cm high, with 1–10 corticated axes 1–2 (–3) mm in diameter. Main axes irregularly radially branched with many lateral axes, lightly to densely corticated, bearing pigmented, basally branched, slender, monosiphonous, attenuate filaments, often denuded below. Holdfast discoid, 2–5 (–15) mm in diameter; epilithic and on solid substrates. Structure. Pericentral cells 5, cut off in circular sequence, at first lightly but below heavily corticated, remaining prominent (Fig. 194B) in transverse sections of the mature axis; in older axes, some of the inner cortical cells may enlarge to the same size as the pericentral cells and protrude between them, thus appearing to have 6 or 7 pericentral cells, and coarse rhizoids later develop between the central cell and the pericentral cells which develop very thick walls; occasionally a space occurs in the centre of the axis when the central cell breaks down. Pseudolaterals one on each segment, 1–6 (–8) mm long, attenuate, usually subdichotomous every (1–) 2–3 (–5) cells near their base, with the distal end of these cells often of a slightly greater diameter than the proximal end, 3–6 (–7) subdichotomies on any filament giving 8–20 ultimate branches, supra-basal cells 30–60 µm in diameter and L/D 1–2, cells after the last subdichotomy 19–25 µm in diameter and L/D 2.5–9, cells of ultimate filament 12–25 µm in diameter and L/D (3–) 5–9. Adventitious monosiphonous filaments usually present, similar to pseudolaterals, arising from the cortical rhizoidal filaments and one, often two, from the basal cell of the pseudolateral; intercalary cell divisions absent. Lateral axes arising from the first branch of the one or two adventitious monosiphonous filaments arising on the basal cell of the pseudolateral, or later from the first branch of an adventitious monosiphonous filament. Rhodoplasts discoid, elongate and often reticulate in larger cells.

Reproduction: Gametophytes dioecious. Procarps borne spirally on successive segments of an adventitious polysiphonous axis, with 2 sterile group initials on the supporting cell but with a 3-celled rather than 4-celled carpogonial branch. Carposporophytes with a slight basal fusion cell and terminal clusters of apical and lateral clavate to lacrimiform carposporangia. Cystocarps (Fig. 194C, D) sessile, appearing terminal or nearly so on a corticated axis, globose, 630–880 µm in diameter with a short wide neck 0.2–0.4 as long as the diameter of the cystocarp; pericarp 3–4 cells thick, outer cortical cells irregular. Spermatangial branches (Fig. 194E) on the lower branches of the monosiphonous filaments, elongate, cylindrical or tapering, 200–850 µm long and 40–55 in diameter, 15–30 fertile segments long on a 1–3 celled monosiphonous stalk, with a (1–) 4–15-celled attenuate apical filament.

Tetrasporangial stichidia (Fig. 194F) on the lower branches of the monosiphonous filaments, lanceoid to cylindrical but usually swollen where the spores are mature, on a 1–3-celled monosiphonous stalk, 300–1200 µm and 10–25 fertile segments long, 100–190 µm in diameter, with 6 pericentral cells all of which become fertile. Each tetrasporangium with 3 (–4) undivided cover cells irregularly obloid in shape (Fig. 194F) , palisade-like, (2–) 3–5 times taller than broad in surface view, covering more than half of the sporangium of the same segment and the segment below, occasionally cutting off a smaller cell at the base when mature.

Lectotype from Georgetown, Tas., Gunn 1263 (tetrasporangial), in Herb. Harvey, TCD (Parsons 1975, p. 568). Isolectotypes in TCD; Herb. Hooker, BM; MEL (Gunn's book).

Selected specimens: Esperance, W. Aust., drift (Finnan. Dec. 1951; AD, A18891). Eucla, W. Aust.. drift (Woelkerling, 5.xi.1968; AD, A33959). Point Sinclair, S. Aust., drift (Parsons, 2.xi.1968; AD, A34179). Elliston,

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

Distribution: Esperance, W. Aust., to Walkerville, Vic., and around Tasmania.

Taxonomic notes: It is probable that many references to Dasya villosa apply in part to Dasya extensa.

Endogenia gracilaria J. Agardh (1897, p. 57, pl. 1 fig. 14; see also De Toni 1897, p. 352), from Port Elliot, S. Aust. (type in Herb. Agardh, LD, 29790) is a very denuded plant of D. villosa, with typical tetrasporangial structure and a few monosiphonous filaments and young stichidia.


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.

AGARDH, J.G. (1897). Analecta Algologica. Cont. IV. Acta Univ. lund. 33, 1–106, Plates 1, 2.

DE TONI, G.B. & FORTI, A. (1923). Alghe di Australia, Tasmania e Nouva Zelanda. Mein. R. Inst. Veneto Sci., Lett. Arti 29, 1–183, Plates 1–10.

DE TONI, G.B. (1903). Sylloge Algarum omnium hucusque Cognitarum. Vol. 4. Florideae. Sect. 3, pp. 775–1521 + 1523–1525. (Padua.)

DE TONI, G.B. (1924). Sylloge Algarum omnium hucusque Cognitarum. Vol. 6. Florideae. (Padua.)

HARVEY, W.H. (1844). Algae of Tasmania. Lond. J. Bot. 3, 428–454.

HARVEY, W.H. (1847). Nereis Australis, pp. 1–64, Plates 1–25. (Reeve: London.)

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

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. (1863). Phycologia Australica. Vol. 5, Plates 241–300, synop., pp. i-lxxiii. (Reeve: London.)

KÜTZING, F.T. (1849). Species Algarum. (Leipzig.)

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.

MAZZA, A. (1910). Saggio di Algologia Oceanica. Nuova Notarisia 21, Nos. 309–368.

PARSONS, M.J. (1975). Morphology and taxonomy of the Dasyaceae and Lophothalieae (Rhodomelaceae) of the Rhodophyta. Aust. J. Bot. 23(4), 549–713.

REINBOLD, T. (1898). Die Algen der Lacepede und Guichen Bay (Slid Australien) und deren näherer Umgebung, gesammelt von Dr. A. Engelhart-Kingston. II. Nuova Notarisia 9, 33–54.

REINBOLD, T. (1899). Meeresalgen von Investigator Street (Slid Australien), gesammelt von Miss Nellie Davey (Waltham, Honiton). Hedwigia 38, 39–51.

SILVA, P.C., BASSON, P.W. & MOE, R.L. (1996). Catalogue of the Benthic Marine Algae of the Indian Ocean. (University of California Press: Berkeley, Los Angeles & London.)

SONDER, O.W. (1853). Plantae Muellerianae. Algae. Linnaea 25, 657–709.

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.

WOMERSLEY, H.B.S. (1966). Port Phillip survey, 1957–1963: Algae. Mem. natn. Mus., Vict. No. 27, 133–156.

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

Author: M.J. Parsons and H.B.S. Womersley

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. 194.

Figure 194 image

Figure 194   enlarge

Fig. 194. Dasya villosa (A–D, F, AD, A32591; E, AD, A33771). A. Habit. B. Transverse section of axis. C. Branch with young cystocarp showing darkly staining sterile cells. D. Mature cystocarp. E. Spermatangial branches. F. Stichidia on pseudolaterals from a corticated branch, showing tetrasporangia and cover cells.

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